The Ultimate Edelbrock Carburetor Tuning Guide

[@Compcams1976]

Great video! Very informative!

[@65Bogie]

I always thought my car ran pretty good and then I stumbled upon this video and realize that my vacuum advance was on the wrong port, what a difference thank you very much.

[@MuscleCarSolutions]

Nice! Glad it helped. Tuning is a process. Keep working the process and it’s always amazing how good an old carburetor will run.

[@skipthompson288]

This is by far the best explanation I've seen on how to adjust an eddy carb. Thank you!!!

[@teddybertgarage4119]

You bet, very useful, thanks for chairing 👍🏻

[@Squares.SSs.and.Bowties]

Super helpful video! You made absolute sense out of the jet and needle chart which confused me until I saw your video. THANK YOU!!

[@tomnekuda3818]

The AFB is the easiest carb to tune I've ever had in terms of an American carb. With their Strip Kit and the charts it is super simple. The only carb I've ever found that is easier to dial in are Webers. I had 42DCOE side drafts on a Chevy I had and, with beer in hand, I found them to be super.

[@mkhy3565]

Thank you. Not sure why Edelbrock stopped putting this tuning chart in the installation manual. It was frustrating just finding it on their website. Need to use a PC, not a phone. This solves alot of issues and shame on Edelbrock for removing this out of their manual. Thanks for the video

[@jondough4116]

Bought mine at summit racing and I got a bunch of Manuels 2yrsvback

[@dukebacher1216]

Sir, First off, thank you for taking the time to help others... We appreciate you sharing your knowledge and experience. I have a 1992 Dodge D250 pickup w/360 (LA, not magnum) engine. It originally came with TBI, and ran pretty well until one day Pfffft. No power to coil or EFI. Literally replaced everything including the computer twice, still nothing. I purchased one of the Jegs HEI distributors (to fit a Dodge), an Edelbrock Performer intake, and at first a Holley 1460 Carb. Holly just pumped gas into the cylinders, and it chugged. Never could make it run right... I am using the stock in-tank fuel pump, going through a filter, a bypass regulator (5psi) , another filter, and then one of those "dial-style" deadhead regulators (just to be sure) before the carb. A buddy gave me a Carter/Edelbrock 9635S 4bbl, (600cfm) which I promptly put a kit into, and the truck is extremely happy. I did have to remove the vacuum advance off the dist. because it would hit the intake or the firewall. I "locked down" the timing slider inside the dist, but it still has centrifugal advance intact. With the Eddy/Carter carb, I can get a really nice idle, but it's a little too low (little under 500 RPM). If I attempt to raise it, it suddenly starts sputtering like it's running on about 4-5 cyl. Same thing happens if you lightly rest your foot on the gas pedal. just a little more throttle, and it's back to smooth, and accelerates quickly. Likewise if slowing down, slight pedal pressure (or being between 550-850 RPM) causes this sputtering miss, then it gets down into the idle circuit and smoothes out, but at really low RPM's. The engine is bone stock, with 160,000 miles, Automatic trans, and runs like a scared rabbit with the Edelbrock 4bbl, except for that blasted stutter just above idle. If I could just get it to idle up a little more and to stop that stuttering, It would be running perfect. Am I going to have to find a way to re-install the vacuum advance, or is there something that I am missing? Going down the highway, it purrs... and is 3-4 times more responsive now, than it ever was when it was TBI. Gonna need to do some mods to get my speedometer and overdrive to work again, as they were controlled by the ECU, but that sputtering drives me nuts! Thoughts?

[@dukebacher1216]

@@MuscleCarSolutions Yes, I did use an Edelbrock kit on it. Strange thing, last night I was going to visit a friend in a rural area... when I got onto his road (straight and flat) I put all 270 foot pounds into the pedal and let 'er howl up to about 80-ish MPH (according to phone app) and it now idles at about 750-800 and no sputter! I will have to figure out a way to make the vacuum advance fit in the limited space I have. I figured the mechanical advance would be ok, but if the vacuum will make a difference... I'll massage the firewall a bit.

[@dukebacher1216]

Latest update: truck still runs perfect, and am getting 12mpg (used to get 8...) now! I've decided I'm not touching a thing on it. (except to add an overdrive enable switch)

[@MuscleCarSolutions]

Nice! Well glad it’s running well. Keep those filters clean and you’ll get lots of good miles on it!

[@ianfurqueron5850]

Thanks for a video. I have a Triumph TR8 with an Edelbrock carb (replacing the OEM cross-ram dual Zenith Strombergs). My carb experience is with other British cars with SU and Zenith Strombergs, and despite dreaming of muscle cars in my youth, this is my first car with an American style 4 bbl. I have been struggling with the car since I bought it last year. I came with no choke installed (manual linkage on the carb, but no cable installed), so cold starts have been a SOB. Once it does start, it runs pretty good, although it run super-lean during cruising. The previous owner installed a AFR gauge which is show the rating well in the 16:1 range (or higher) at speed. The temp gauge will also creep up almost to the point of over-heating. Oddly enough, in stop and go traffic with the engine idling, it richens up (13:1 or so) and the temp gauge is perfectly normal. While watching the video, I paused it and went to look at the vacuum ports. Passenger side - capped. Driver side - open (with the vacuum hose to the distributor disconnected. The large center port - also open. Rear port - plugged (the power brakes are connected to a port on the manifold). Something tells me that completely open center port would represent a large vacuum leak? I know from my years fiddling with SUs and Z-Ss, vacuum leaks are the bane of carburetors. I swapped the distributor line to the passenger side port, moved the small cap and capped the large port. I bought a tuning kit, but now I'm wondering if I really needed it... unfortunately, my interior is apart (fixing more previous owner "mods"), so it'll be a day or so before I can start the car and see if the capped ports makes a difference. I wonder if a phenolic plate between the carb and the manifold might help, but unfortunately the space under the hood of a TR8 is tight.

[@MuscleCarSolutions]

You’ve made the right choices and corrected some horrible issues with the vacuum leak in that PCV port up front! Yes, you absolutely need the tuning kit. You have a great advantage there with the AFR to help you tune once you get ready. Yes a block for the heat transfer is important. There is a link in the video description of the narrowest spacer that Edelbrock makes. If you can use it, anything helps!

[@ianfurqueron5850]

Thanks, I'll take a look at the spacer. I also need to check the timing and advance are correct. It's funny - a common saying from working on old British (and Swedish) cars is "90% of carburetor problems are ignition related." Especially since many of these cars are still running points distributors.

[@MuscleCarSolutions]

@@ianfurqueron5850 that’s a statement that proves itself true over and over again! Good luck, and if you run into any issues don’t hesitate to let me know. Always happy to help if I can.

[@c.pc.5805]

Sir I love the idea of 2 fuel filters this way everything is protected.

[@harvestblades]

Especially for those of us running original gas tanks on forty year old vehicles.

[@happysailor9858]

Man...THANKS!!!! You have delivered a super informative well filmed session again. I've the way you explain these things.

[@trifivegarage8683]

Thanks this video has some very good info. I found lowering the fuel pressure to 3lbs. Helped the hot restart issue as well. Doesn't seem to creep as far up after shut down. The ethanol fuel is causing a lot of problems. For those of us running carbs these days.

[@trifivegarage8683]

@@MuscleCarSolutions OK.. I think I will give that a try if I continue to have heat soak problems. Summer is coming and it gets pretty hot here in florida. I'm running the shorter edelbrock spacer 3/8" for the EPS manifold. I have plenty of hood clearance still. Thanks.

[@bryanroupe8646]

A 1 inch spacer should help. I run them on everything.

[@bobjackson4171]

Fantastic! Well explained, at a 5th grader level. I wish other folks making vids like this were such good teachers.

[@MuscleCarSolutions]

@@bobjackson4171 well I mean I wasn’t trying to act like anyone watching is a fifth grader. 😂 But I’m glad you liked the video. I’ve got TONS more on Edelbrock carburetors. 👍

[@bobjackson4171]

@@MuscleCarSolutions Lol! Maybe you are more intuitive when making your vids. If the goal is sharing knowledge, then you certainly “get it” sir. I liked, but did forgot to subscribe. I will go do so now! : ) I plan to watch your other vids as well. Thanks for expanding my knowledge and capabilities that will come from it!

[@MuscleCarSolutions]

@@bobjackson4171 that was the whole reason why I started uploading videos. I get a ton of satisfaction when I can help folks. Don’t hesitate to ask any questions along the way. Always happy to help if I can.

[@bobjackson4171]

@@MuscleCarSolutions Thank you! I might take you up on your offer as I go. Thanks in advance!

[@denisonjesse]

I installed edelbrock wood spacer and fuel pressure regulator like the video suggested. Now my chevelle runs better. Great video !!

[@MuscleCarSolutions]

Nice! Good work!

[@rogjackson]

Stock 1413 (800cfm) on 454 BBC mild cam street car with a T350 automatic transmission. Incoming fuel pressure is 6.5 ish. Ran perfectly for last 5 years accross all throttle positions/weather conditions. Recently, (warming in Northern CA) I get a hesitation from a standing stop to full power (iow punching off the line), but it does go for just a second before the hesitation. Then after the hesitation, everything is fine. From cruise to full throttle no problem. So it's just a hesitation from standing stop to full power, but the hesitation doesn't hit until about a second off the line. Carb looks clean generally and I've never adjusted a thing because it has worked perfectly up to now. Thoughts? Educated guess? I appreciate anyone's input. Cool video!!

[@MuscleCarSolutions]

Ah these conversations always hurt my feelings. 😂 Imagine how much better it will run when you tune it! What’s your engine vacuum at idle? Match the step up spring to it. Then you can adjust from there to remove any hesitation. What is your initial timing set to? When does fill advance come on and what is it? The pressure is on the high side. Just be aware of that if you start having issues. I’d start there and you can work through the tuning process to really get it dialed in. You’ll be surprised what you put up with as “normal” once it’s been tuned for your application.

[@cbobmonster]

Dude, you are freaking amazing and knowledgeable. Great video I sent you a common earlier about stumbling and backfiring on acceleration and it just started happening Dodge 318.

[@maximuswedgie5149]

This is a fantastic video that I’ve been looking for. Tomorrow morning I go pick up my 1408 or 1480? Edelbrock tuning kit. I had no idea where to start now I do thank you very much. I put a new 383 ( with bigger cam and roller set up)in my Mopar and I got a terrible stumble off the line. I can’t even put it in gear unless it’s almost 1200 RPMs at idle without it dying. I will be referring back to your video and I will hope that my kit comes with that book. If not I will download the PDF as you said. Thanks again for the great video sir

[@MuscleCarSolutions]

Well you’ve got some work ahead of you but the good news is with some patience and a little understanding, you’ll be able to get it running and driving much better. Don’t hesitate to ask any questions if you get stuck. Happy to help if I can.

[@MuscleCarSolutions]

I’ve got a ton of Edelbrock carb videos and fuel system set up in a playlist. You might find some of those useful too. Good luck!

[@maximuswedgie5149]

@@MuscleCarSolutions I will definitely check the other videos out👍🏻 thanks for the reply

[@waynep343]

put a 10 micron fuel filter before the mechanical fuel pump to keep sediment out of the fuel pump check valves.. 1984 corvette fuel filters are 10 micron.. when sediment gets in the check valves the fuel pressure held by the pump in the line to the carb is reduced. this reduction in fuel pressure allows the fuel in the line to the carb to boil.. the expanding vapor pushes liquid fuel backward thru the fuel pump.. .leaving the carb low on fuel. this reduces fuel boil over and hard to start engines because they are flooded.. when the sediment in the fuel pump gets thru to the needle and seat.. it can when the fuel level is reduces allow fuel vapor to expand and overflow the carb.. if you have an off idle stumble with an edelbrock.. cold engine count the fractions of turns to lightly seat the idle mixture screws.. take them out.. with a can of carb cleaner.. blast a 1 second spray down the idle mixture screw hole... 1 SECOND.. followed instantly by a blast of compressed air. do this 2 or 3 times for each idle mixture screw hole.. this blows sediment out of the idle feed restriction and the idle air bleed. in the primary booster assembly. if you have flat spots and you are running an engine over 360 cubic inches.. and especially over 400 cubic inches.. you may have to use a 61 to 80 drill set and one size at a time drill the idle feed restrictions in the side of the primary booster assemblies. its behind the idle air bleed on the side. you want to take the top off the carb.. then take the primary boosters out.. 2 screws. figure out what size the second part of the passage is. go up 0.001 .. reassemble and test drive .. you will need to readjust the idle mixture. the idle speed then test drive. if you get a flat spot at around 1000 or 200 above base idle.. or up to about 2200 RPMs before the primary circuits take over completely.. keep drilling 0.001 at a time. look up Low speed circuit.. look up idle transition circuit.. look up economizer circuit. edelbrock and holley removed this info from the carb manuals to allow the carb tuners something to work with. .

[@rumbador]

I’m about to install a 1406 carburetor to a stock 327 engine hope don’t run into a lot of trouble. Great video will help me a lot

[@rumbador]

Definitely will take your advice about putting two filter. Thank you

[@rumbador]

Bone Head can you recommend me one in particular

[@ArnCital]

There is a lack of information on A/F ratios vs power and fuel economy with regards to stressing the engine (knock, ping, burned valves). For example what is the best A/F for fuel economy while cruising without leaning out the engine too much? My truck is a 1985 F-250 HD (5,900# certified scales) with a fresh 460, T-19 4-speed, 4x4, high boy, 9:1 c.r. with forged pistons, mild cam, stock heads/exhaust. Dyno at 4,200' is 246 HP/4,200 rpm at the rear wheels (Dana 70 rear end) and max torque at 2,500 cruising rpm. Best number for fuel economy I could find was 15.4 A/F. I leaned out a 1405 to one stage leaner (at 4,000' elevation) and the truck will get up to 11 mpg and runs strong. That said, 200 miles on fresh plugs shows the porcelain insulator to be a clean white and not a light grey or brown that is optimum; the ground electrode has a slight buildup of deposits. There is NO ping or knock so I am good there. My point is that it is a good idea to read the spark plugs while tuning. I may be just slightly too lean and will experiment with rods and jets. My AutoMeter A/F shows 15.4 A/F when cruising and above to 16 with slightly more power for passing, etc. WOT power and idle is 12-13. Had I installed stainless steel or stellite-faced exhaust valves then I would not worry too much about being slightly lean. If you cannot measure it then you cannot troubleshoot it, you can only guess and I hate guessing. I am still looking for a good book or read on A/F tuning.

[@ArnCital]

@@MuscleCarSolutions Thanks for the rapid response. I have planned on lowering the A/F ratio. Nowhere on the internet or library have I found studies of varying A/F ratios and effects on driveability, engine load, engine damage, and so on. I am an industrial engineer and dealt with numbers and not opinions. That is why I monitor the A/F and vacuum along with load and rpm. Too expensive to add a gear. BTW, the engine is built as strong as I could with Eagle rods and Autotec forged pistons. It is capable of handling 550 HP and I have about 300 HP at the flywheel. Timing is 8 deg BTDC on a stock dizzy. After observing retaliative coarse A/F changes with the EDDY then I am now considering EFI because I can fine tune the engine fuel parameters.

[@garlandjones7709]

What an engine desires for a/f is not a static/constant number. Each engine will like a different number. Anyone can get you ballpark, but in the end, it's similar to timing There's not a magic rule outside of experimenting. Called "tuning"

[@dbriggs1689]

Fantastic video thanks for the advice. Im starting this journey on a 75 f100 with a mild cam 460. So far ive determined its an old edelbrock 600cfm but i got ignition maintenance to get sorted out first.

[@MuscleCarSolutions]

Yup. If you get the supporting systems right first (ignition and fuel supply), tuning becomes very easy. Good luck! Don’t hesitate to ask any questions along the way. Happy to help where o can.

[@dbriggs1689]

@@MuscleCarSolutions Thank you.

[@crash1769]

very informative. I finally understand in plain english the tuning chart. I have had number of people explain this to me but couldn't understand it until now. thanks Muscle car solutions.

[@MuscleCarSolutions]

Good deal! I’m glad it was well received. I’ve worked on these carbs since I bought my first one in 1989. I still use that chart every single time I tune one. Extremely valuable!

[@wesleewilson_]

Great video! I'm reading through the manual and trying to wrap my head around how this carburetor works. Do you have a simple explanation for what components effect which driving conditions? IE: idle mixture screws determine idle afr during idle, but also; primarily jets effect this too? Then when accelerating, springs and metering rods kick in. Then, during wide open throttle, primary, secondary, and idle mixture screws determine afr. Am I correct here? Basically, I'm trying to narrow down what to change by looking at afr during different driving conditions. Also, what is a good afr for each of these stages when shooting for fuel economy?

[@shadvan9494]

I find the Edelbrock carbs tend to be too rich from the factory. my tuning method is to get the engine to operating temperature. set the timing using the total timing method with the vacuum advance disconnected. then get a measurement on vacuum and install the recommended piston spring. I then set the choke to full open so the choke will not affect tuning. the use a AFR gage like you recommended to set the Idle. I like my idle around 14.5:1 for best efficiency and lowest emissions. Then I find a nice flat open stretch of road or freeway with low traffic and cruise at 35-40 mph and take a reading, then 50-60 mph and take a reading, attempting to keep the pedal in the same place to eliminate as much fluctuation as possible. the reading should be pretty close, I use that to set the air fuel ratio for cruise. i like 14.5 to 14:1 the using that same stretch of road, I start with cursing at speed and then roll into the throttle a bit but not opening the secondaries. think of it as passing a car on the freeway. I want to see the AFR gauge drop to around 12.5-13:1 then gradually come back up as the engine increase rpm and vacuum recovers to pull the pistons down. lastly, I use test and tune nights at the drag strip to dial in the secondaries. with all 4 barrels open i want to see my AFR between 12.5-13:1. if there is any bog or hesitation off the line, at this point O increase the size of the squirters or possibly changing the springs. lastly after the car has cooled down to room temp, i set the choke per the factory instruction, and then in winter i fine tune the choke setting to make sure it starts with very little effort on a cold day. I have also found that sometimes you need rods or jets that are not included in the tuning kit. Edelbrock makes a very large assortment of rods and jets, but they are not all included in the tuning kit. I have also found that sometimes i need a summer Tune (leaner) and a winter tune (richer) to make things run right. I just document what i had it at before and then return it to that setting at the end of the season. this same process also works on a Quadrajet, you can still get Performer Q-jet parts from Edelbrock including rods, jets, springs, hanger, etc.

[@MuscleCarSolutions]

Wow. You really like your AFR on the extreme lean side. With todays fuels, I don’t know that I’ve ever met anyone who’s willing to take that chance.

[@markusgarvey]

You forgot to mention not only pressure but volume of fuel as well. Especially if you lower your float level. I had an issue where the pressure of the stock mec pump was fine under normal conditions, but there was not enough fuel volume when under WOT. I added a booster pump, or you can just eliminate the mech pump. Personally I like redundant fuel pumps. And you dont need to install a return. This was on a Pontiac 409 w/ 068 tri power cam and Edelbrock 750.

[@MuscleCarSolutions]

Mark Estrada absolutely flow is critical. I mentioned in a recent video that’s why I run Aeromotive pumps, filters and regulators. They flow well across the pressure ranges in all instances. There’s only so much you can put in a 16 minute video. High level basics on this video. Everything in steps.

[@chevylandtv670]

Can someone help me out! I have a brand new avs Edlebrock 1406 on a stock 305 with a computer delete my idle n park is high but when n drive it pretty good, also my clothes smell like I been riding a dirt when I stand by the car also I’m seeing smoke come out the carb when I shut the engine off using an aluminum quadrajet spacer this is a brand new Edlebrock carburetor straight out the box any suggestions would help

[@MuscleCarSolutions]

Sounds like you’re into the transfer slots at idle which would cause the rich condition. Keep in mind the 650 is too much carburetor for a stock 305 so you’ll be fighting the rich condition for awhile.

[@tylerhutchinson3646]

Hey I just put my create 5.8 in with a 1406 Edelbrock. Now I know it's really set for economy. But I ordered rods and springs. Your videos have show alot. But I'm getting a feel for my next step. I thought I had it tuned pretty good but iv got this stumble in each drive and idle that I'm trying to work out.

[@MuscleCarSolutions]

Yup. Keep tuning. You’ve got the tuning kit and that’s a great start. Make some changes to the accelerator pump. I did a video on that. Adjust fuel pressure. Did a video on that as well. Keep working with your timing as you make adjustments that get you good results. You’re a little limited with the older performer series carb on the secondary side, but you still have lots of tuning points to get it dialed in. As long as the cam profile isn’t too wild, and what you’re using it for, you’re on the right track.

[@shellback2002]

Sir, I found your video along with the Edelbrock manual extremely useful. I have a '78 Ford F 150 400m engine and C6 transmission. I just had the heads properly freshened with hard seats, guides etc. I updated the engine with a Comp Cams RV style cam and timing set, Pertonix distributor, Edelbrock 3771 4bbl manifold and a 1406 carburetor. Once the vehicle was running, Initial curb idle timing set at 12* BTDC without the vacuum and 36* BTDC with vacuum at 32-3400 RPM, idle mixture set for max vacuum I have encountered 2 issues. There was a soft lean misfire at light to medium throttle . I have solved that satisfactorily by increasing the metering rod 1 step straight North on the calibration chart from the stock 7547 to a 7347. The unresolved issue is a light misfire during the transition from closed throttle to about 1/3 throttle. I find that little burble irritating particularly at cruising speeds. Thanks for your time

[@shellback2002]

Bones’ Thank you for your prompt reply. I do not think the misfire is back through the carburetor, it doesn’t feel acute enough for that. think your suggestion of timing and hose routing is an excellent next step. Currently The vacuum source for the vacuum pod is from a true manifold vacuum source through a thermostatic valve to the pod as illustrated in the 2 photos. The plugged hose went to the plugged nipple on the carb base.It goes to a vacuum router at the rear of the engine for EGR and EVAP that I found had a significant vacuum leak. image2.jpeg image1.jpeg The vehicle has passed emissions inspection so I can move things around as I please. Would you suggest vacuum to the pod directly from the manifold vacuum port on the carb base. Unfortunately this will be the only adjustment I can make for the next 2 months. My son the owner is a Chief Engineer on a container ship and goes back to sea on Friday. The truck will drive N 130 mi and then sit in the ship yard for 2 months. I’m a retired European automobile mechanic and shop owner. This has been a fun project for the Chief Mechanic and the Chief Engineer. I do so love EFI! The cars I worked on sold their last carbureted vehicle in the US in 1972 right at the end of my apprenticeship.....lol. Thanks again for your knowledgeable input. I’ll keep you posted as progress is made. Disseminated from Zubenelgenubi

[@shellback2002]

I guess the photos didn’t go through. The vacuum source is a fitting on the #5 intake runner.

[@shellback2002]

@@MuscleCarSolutions Excellent suggestion! Thank you. I have now put the Vac pod hose on the correct nipple on the carb. It now runs significantly better. I think I will go back to the original 7547 rods and give that a try when my son returns from sea and brings the truck back. Thank you again for your on point and wise counsel. If you ever deal with SU carburetors give be a ping. That was my world back in the day. Cheers Bo

[@shellback2002]

Bone Head, I think I will purchase one of your suggested A/F ratio measurement systems to aid me in dialing in my sons truck when he returns. I think I can also figure out a way to use it with my boat engine which is a Chrysler Marine 318 with a 1409 carburetor. Once again thank you for your wise council.

[@coachk7674]

great stuff, I have a new 1406 Edelbrock on a 72 K1500V8, 350, 5.7 etc. manual choke cable and have recently moved from sea level to above 9200 feet. today for the first time it would not start and drained a battery trying. before I start over, my question is: does the high altitude affect the cold starts?

[@MuscleCarSolutions]

It affects every operation on a carb. Absolutely. Higher elevation means less oxygen. You’ve got some tuning to do!

[@car_ventures]

Thanks for putting this together. Struggling to get mine running nice on a 350 sbc. Spent a couple of hours just now. At idle it smells rich, going leaner causes the engine to run rougher / close to stall. Also hesitates momentarily when throttle blipped. Going rich means throttle blip is ok and smooth, but kicks some smoke out and idle smells of unburned fuel. Feel like I've been going around in circles (adjusting idle speed along the way as rpm drops / increases - aiming for 600 / 650 idle rpm in park).

[@car_ventures]

@@MuscleCarSolutions wow thanks for the quick reply! Engine has stock cam, edelbrock performer intake and carb, headers and 2.5" exhaust with X pipe and flowmaster delta 50 mufflers. Adjusted timing a few times, seems to be pretty consistent aka sits at 12°@ idle and 36°@ ~2500rpm. Have only been adjusting the front two mix screws and the idle rpm screw so far to try and get it consistent... i.e aiming for no fuel smell @idle, smooth throttle response and smooth idle. Is it likely the answer lies in rod / jet changes?

[@car_ventures]

@@MuscleCarSolutions The carb is a 1406, so works out to a pretty typical SBC upgrade with the intake and headers. It was fitted to the car before I bought it, so not sure if it's got the stock jets in there. Think I'll grab a kit from Edelbrock with all the rods etc. I'm in England so takes a while to get over here from the U.S. Might do a video of it running with a vacuum gauge on and share it with you for feedback. Carb tuning a V8 is not too common over here :)

[@kylerrichardson4858]

Resurrecting this masterpiece. Ive assembled a new 400 with higher compression and a mild (276) cam, as well as this AVS2 carb. What would you recommend as a starting point to ensure I can fire up and break in my cam right away and not wipe anything dry trying to fire it up the first time? *edited for typo

[@DeanBishop-gb9mx]

Great video, I just finished building a first gen 350. I have it in a run stand and as a project want to learn my edelbrock carb and how to make it right. I assure you that you will be hearing from me with questions. Can you tell me the best way to communicate with you. Thank you

[@MuscleCarSolutions]

Best of luck! They’re actually very easy to tune and work on. I’ve got a whole playlist of Edelbrock carburetor content. Just drop any questions in the video you’re watching. If I get the notification, I’ll respond.

[@ericdolby1622]

Wish there was a guide like this for tuning a 1405 on a huge cam Chevy 348

[@CORNDODGER]

Damn I needed this I just put a 2 inch Spacer on my engine and now it seems to lean out way to much around 4000 rpm and my shit point is at 4500 just ordered a complete kit from speedway

[@TandD1w]

I was very tempted to get the AV2 carb, until my tuner shop recommended against it for the carb boiling issues. Did some searching and came up with a Edelbrock tech page addressing this. Now you mention it as well. Now, I'm wondering just how big of a problem this is. Maybe this isn't the right choice for my iron manifold application.

[@TandD1w]

The techs argument was the Edelbrock places it’s fuel bowl directly over the carb flange whereas the Holley places it’s bowl off to the side. The Holley has more separation from the flange so there is a longer thermal path and the Holley has more surface area of help remove the heat from the bowls. His argument does seem to have some merit. Personally, I’m liking the carb because I don’t have to dump fuel every time I change a jet and it’s supposed to hold its tune better.

[@lancestone540]

Recently purchased a nicely restored 68 Mustang with 5.0 and Holley 4barrel carb. Both front and rear bowels were running over a bit. I lowered to floats to stop that. Adjusted the electric choke a few times. Had it running fairly decent I thought. Had been threatening to get rid of the Holley. I had been driving it around that morning and it ran pretty good. But then it seem to run badly after stopping for lunch. Drove over a short distance to the chiropractor's office. Upon leaving, the car would not crank. I thought maybe it had flooded? I removed the breather, closed the hood. Tried to crank it and the BOOM. THE ENGINE BACKFIRED AND THE NEXT THING I SEE IS FIRE UNDER THE HOOD. Thankfully the girls in the office came to the window only to see me trying to smoother the flames out with my coat. They quickly brought me out some water. Finally got the fire out. Of course the hood will need a repaint. Other than that not much damage expect I need a new coat also. Estimator will be out tomorrow to check it out. We will see if State Farm will treat me like a good neighbor 😊. NOW ....after watching this video I can see I need to add a fuel pressure regulator and more filters. It only had a small one between the pump and the carb. Think I'm going with a new Edelbrock.

[@lancestone540]

Oh yes, the spacer. Thanks for reminding me. I'll have that black beauty back on the road in no time. Thanks for the great video 👍

[@therealbadbob2201]

I have a 318 with a torquey cam and magnum 360 heads. I have not been able to get the stumble off idle to go away, but at 2000 rpm if I kick her in the guts she absolutely screams.

[@Jacob-dq4cs]

The real Bad Bob I have the same problem in my big block, she doesn’t like to take off but once you get past 2000 hold on lol

[@rustyridesgarage672]

I live in Loveland Colorado whereabouts should my Jets be setted for a 600 CFM Edelbrock running into tunnel ram running into stock 350

[@obsessivegarage921]

Hey watch your videos all the time. Love them thank you very much. Quick question, I have a 1406 Elderbrock carb, I was told to tune it using the 1405 chart, possibly on #1 setting or even #2 or #9, which take the .100 jet and .068x.042 rod or .070x.047 rod etc to get better performance out of it for my 70 Nova. (350 5.7 Vortec, high rise intake, long tube headers, roller cam) And the #1468 accelerator pump as well. I'm about to rebuild my elderbrock carburetor soon and I've been reading up and re-watching a lot of your videos. Thx for any tips are help, you're awesome 👌

[@cbobmonster]

I know this video was a long time ago, but just curious my 318 Dodge under acceleration is sputtering and backfiring once in a while and it just started doing it was wondering if you had any issues excuse me information it’s got an AVS to Edelbrock on it

[@MuscleCarSolutions]

@@cbobmonster don’t know. Could be a number of things. Verify timing and ignition components. Once an engine is under load, that’s when it puts stress on ignition system components. Bad grounds can cause this as well. That’s where I’d start. Then you can start looking at fuel. If it’s a lean condition causing it, it could be fuel filters are clogged or restricted. Fuel pump might not be able to keep up when the fuel demand increases. Garbage blocking secondary jets. Step up springs are incorrect or need a change to a different rate spring. You can also add in potential vacuum leak(s). Start working through and eliminate the possibilities until you find the issue.

[@reriley2002]

I’m running dual edelbrock Avs 500’s on a pretty stock sbc. I have a stumble right off idle if I nail the throttle. If I roll into the throttle, it burns the tires. The plugs are all nice and tan, msd, vac. Advance distributor, timing set at 10 deg. Btdc. Full advance is 36deg. By 2500 rpm. The chrome headers are turning blue, which would indicate lean to me. Where do I start? I do not have the book as I bought this whole setup used. I am assuming that both carbs. Have the stock jets, springs and rods, but I have not verified that yet. The pump shot linkage on both carbs is set in the center hole. Electric fuel pump, regulator with gauge, 2 fuel filters, and aluminum 1” carb spacers. Running 4psi of fuel pressure.

[@MuscleCarSolutions]

Lots of questions and places you can potentially start. I’d add some more initial timing to start with. It’s time to begin to look at tuning the carbs as well. I wouldn’t rely on the chrome headers being a good indication of a lean condition. In my opinion, the only way I will tune any dual set up is with an AFR. Preferably a dual O2. I know they are very expensive but it’s really the best way to tune those carbs and set timing. I know 30 years ago Dad did it all by ear but there is a wild card in all this - we have horrible fuel today with ethanol. So consider that investment if you plan on keeping that set up.

[@michaelnowak3570]

I am trying to cure a slight stumble off idle. Open it runs really well. Idle can be slightly rough after I adjusted mixture so that is better. Timing is on. The just off idle is not smooth into power.

[@MuscleCarSolutions]

Have you made any adjustments to the accelerator pump to verify if you need more fuel or less?

[@bdavis12758]

This is a great video. I recently swapped a 06 5.3 in my 1980 k10 which I swapped the fuel injection to a carburetor. I opted for a Holley mid rise intake, edelbrock 1406 carb, and msd 6014(I believe the number is) ignition controller and once I got my batter ground figured out, she fired up no problems.... I’ve yet to adjust it any means being in Kansas I have no idea what the tuning is gonna be..... I’m in Europe on a 9 month rotation and all I read is my carb book so when I get home I can tune with no reference(it’s a small goal I set for myself).... anyways I enjoyed the video. I have a suggestion, maybe tuning idle mixture and determine if you need a new jet. And what is a good baseline for inches of mercury which I believe is 20.5 inches.... I may be wrong but that’s what learning is all about.......

[@bdavis12758]

Bone Head okay I understand. So you could really diagnose jet and rods by dyno, a/f gauge, and driving it.... like I said, I know a little about carbs and trying to learn as much as possible..... For the carb conversion, yes everything is stock.... you’ll need to reroute the vent tube of the driver side head, change the intake of course, and bit an ignition controller..... Holley has a similar setup for the atomic efi which i didn’t want bc it was expensive, and a waste as I’m not trying to go high horsepower.... just a beater with a heater and a little pep in her step....

[@bdavis12758]

Bone Head also, the carb was a reman from edelbrock from jegs.com and only has 3 starts and a 2 minute idle each start bc I don’t have a belt tensioner therefore no belt to spin the water pump and so on.... then left to Europe and have some parts waiting for me if my wife doesn’t sell them 😂

[@bdavis12758]

Bone Head well I had it running just not long enough for the choke to open up so it was a high idle at 1600rpm. I have to adjust the fast idle ad get the idle screws perfect..... I know someone with a similar setup and it’s just awesome. Except he he’s a bigger carb......... I’m pretty sure the 600cfm should be fine on a completely bone stock 5.3.... I’ve seen 750’s on a 305 and other 327’s and they were fine..... if anything, I’ll have to buy a bigger carb.... I want to put a cam from an ls6 with better valves springs bc I love high reving v8’s.... just enough for towing a little and mainly a daily driver.... I’m looking for an nv4500 but people want so much money for that transmission without a bell housing.....

[@armandomendoza3167]

Will this eddlebrock tuning guide work on a Rochester? I've noticed the the numbers kind of match on jets. Rods I can't remember. It has been years since I worked on a carburetor. I'm thinking of a EFI conversion to a carburetor set up.

[@pooroledaddyfishing8132]

Great video, very helpful in understanding the chart. What should the timing be on the 454 I have, the vacuum advance is plugged at the distributor and both caps on the carb

[@pooroledaddyfishing8132]

Bone Head , I think it’s a regular gm distributor when the motor was put in they said I didn’t need the vacuum advance part. Coil pack on top of distributor. I didn’t know if I needed that to be hooked up .

[@haroldlucas239]

Thank you for your video. I have a SBC 383 Stroker. I'm also running a pair of Edelbrock 600 CFM carbs on top of a Weiand 671 blower. Right now my tuner has 62 jets in the front (primary) of both carburetors and 72s jets in the back (secondary) of both. We have the metering rods out but we left the plungers in. Timing is set at 27 degrees advanced. What is your opinion on this setup, have you ever heard of a setup like this. Just would like this hear your feedback if possible. Thank you,. Jr.

[@tommyyarbery379]

So I have an edlebrok 1404 every since I installed it it's ran like crap. I don't have a rpm gauge (77c10). I've adjusted the air/fuel screws a thousand times but the idle continues to hunt, ive checked timing, vacuum leaks ECT. I've installed the adapter for the 1404 on the intake. All 4 opening on the intake are about a little less than a 1/4 in blocked by the gasket(maybe that's the problem?) I've made it back fire through the carb twice and both times the truck ran fine after words. But after about 30 min it's back to running hunting. I'm at a complete loss on it. The original carb was a quadrajet 600cfm the 1404 edlebrok is 500cfm. Maybe under cfm? I went back and forth between air ratio screws idle screw and timing for around 3 hrs lol all the hoses are in the correct spot and timing is correct according to the air cleaner cover(2° for a 350) also switched it to the second hole down on the acc pump for a bigger pump of gas (which helped steady idle alot) any input is much appreciated (77 c10 350 stock intake edle brok 1404 with adapter plate to intake)

[@tommyyarbery379]

@@MuscleCarSolutions the pressure regulator I have no idea honestly, I added one after the pump before the carb recently, I have not took apart the edlebrok yet and the back fire only happens through the carb if I rev it a couple times while it's surging.

[@tommyyarbery379]

@@MuscleCarSolutions I've set and reset the timing to 2° Everytime I turn my idle up or down

[@tommyyarbery379]

@@MuscleCarSolutions no I never added a pressure regulator, everything on the engine is stock except the 1404. I added a new filter between the carb and the fuel pump when I installed the edlebrok about a month ago. There is another one before the pump that I changed about 6 months ago while I still had the quadrajet on it.

[@tommyyarbery379]

@@MuscleCarSolutions alright alright thank you very much, I'll get back to you as soon as the funds are there for me to buy parts

[@tehyoyopro]

I found that when the ambient temperature was between 0-30 degrees (f) my 350 sbc ran great throughout the rev range. Now that it’s 60 degrees (f), at around 2000 rpm the engine backfires out the exhaust and sounds like gunshots. Thoughts? All ignition components were changed in the last 2k miles

[@tehyoyopro]

Bone Head I’ve got an hei distributor. I’m starting to suspect the vacuum advance diaphragm may be failing due to the engine falling on its face above 2500. Also takes more pump shots to start than it used to

[@marks-yw5ij]

I'm very new to figuring out how to set up/ tune my edelbrock carb. I sont believe me secondaries are opening. When looking down the carb and going from idle to about 5500rpm I dont see them opening. Is this right? How can I fix this ?

[@sidecarbod1441]

10:10 The tuning chart for the 500 carb has got at least 3 errors in it! If you work out the area of a jet and then the two cross sectional areas of the rods you can work out the flow area for any given combination of jet and rod, you can then compare this to any other combination. I use an XL spreadsheet to work all of this out, it has shown that the percentage figures of change that Edelbrock quote in their chart is sometimes wrong!

[@skipthompson288]

hahahaha the 14 people who don't like this can't adjust their holley carb and they just found out how easy an Edelbrock is. LMAO

[@KStewart-th4sk]

@Skip Thompson Up to 36 as of 12/11/2019. Funny, a guy called Bone Head can and they can't. LOL

[@jaoojoao5361]

In my opinion holley gets a better adjustement but really like them both ,edel for the streets holley for the strips

[@hanger44smba78]

My truck surges when driving. I'm running a 600 4bbl edelbrock. What do you think it is. It feels like it runs strong then skips on and off running on all 8.

[@erik9685]

I have a Carter AFB 650. It is rather new and has not been used. It has been sitting since October 23. My problem is i just installed a new small block in a 1970 chevelle. And i got the car to run. It takes about a dousen times to turn over before it fires up and runs. There is a POPING noise comming from the exhaust pipe. I believe its comming from thec passenger side pipe. Is that a carburetor issue? How do i handle this issue?Is the poping noise a symptom of the car running rich? I set the timing @ degrees and the total timing is at 32 degrees at 3500 RPM with the vacuum advanced disconnected.

[@steelmill]

Good info,set that base line first then save the carb for last.Dont forget that pesky distributor cap and rotor.

[@luizfernandopaquieli3709]

It's a great explanation! I have an Edelbrock 14053 on a Ford 302 and I couldn't remove all jets, they stuck and broke down inside of it. Did you face any issue like this?

[@cudatom9290]

@@MuscleCarSolutions How do you drain the carb. do you take it off of the motor or do you have a trick?

[@thebighair37]

Your have enjoyed and learned from other vids of yours. To the point of now having two questions... 1) Do all AFB and AVS carbs basically start with the same base/body, but only the jetting and metering rods are different? 2) If this is true, can I take a 1906 AVS2 and turn it into a 1903 by getting the 1903 Calibration Kit and just step the 1906 down?

[@MuscleCarSolutions]

You can change the CFM of those carburetors. That’s a fixed number that remains constant no matter what rods, jets, springs, squirters you change.

[@thebighair37]

I'm sorry, I'm not following. You are saying the CFM can change, so what is the fixed number then? Is there a typo or am I just missing something here? Thanks

[@MuscleCarSolutions]

@@thebighair37 typo. You CAN’T change the CFM. It’s fixed.

[@DesertRatFabrication]

Hey Bone, I am about to rebuild my Edelbrock 1406 fuel pressure is good, will be changing filters as well, the biggest problem I was having is a chugging when driving on a flat surface at about 10 miles an hour, not real bad but noticeable, with that being said as soon as I give it some gas snaps to life, so I thought I would just rebuild the carb, sense I just bought the truck a short while back (55 chevy big window), what do you think, thanks Mike

[@DesertRatFabrication]

Bone Head right on, thanks, should I try it the way it is after the rebuild first , probably ya

[@DesertRatFabrication]

6 psi

[@DesertRatFabrication]

6 psi

[@DesertRatFabrication]

But I only have the 8139 filter

[@DesertRatFabrication]

Is it ok to put both filters and regulator under the hood

[@thedobermangang3503]

i got 1990 k5 blazer 5.7 had it rebuild with a few up grades everything is pretty mush stock i up graded the cam to a howard cam rattler lift 225/230 duration 0.50/227/235 centerline 03 i still have the factory swirl port heads i got headers 3' pipes all the way back i up graded my torque converter to 2000 to 2400 stall and 4:10 gears i just put my engine in about a week ago it was a tbi so i converted it to carb...im having problem trying to get it to run right i put a brandnew edelbrock carb 1406 on it..i got 12-887 holley regulator set it to 6 psi i got it to run starts up good but its backfiring and popping out my exhaust ..i have a vacuum port on my regulator but did not hook it up dont no if thats the problem or not..or is the carb to small for my set up...you can smell the burning and the raw gas in park when u accelerate and give it more gas it sound good but at idling its popping and backfiring like someome popping fire crackers..tell me what you think

[@DesertRatFabrication]

And also what do you mean about the set-up spring to control the transition between cruise and power, thanks

[@andrewpapke8051]

I am running dual avs 500s on small block ford and tunnel ram. Would love some more info on a side chat.

[@nathanm3591]

Nice video and to the point. I have a 500cfm on my Rover/Buick v8 3.5 Defender. The carb is probably a little too big for the motor and tends to run visibly rich. You mention about boil off, i was unaware of this condition. I assume this is why it takes a fair amount of cranking to fire up after being parked for a few minutes, i will fit a spacer and see how things go. I am about to install an afr gauge and getting the tuning set correct. Your explination of the chart was valuable. In your experience, is it worth getting jet/needle tunning kit or just buy individual needles and jets?

[@sidecarbod1441]

The 500 carb can be made to work very well on a Rover 3.5, it is just jetted to rich out of the box, in fact why would you expect it to give the right fueling out of the box anyway? I've setup loads of these carbs on 3.5, 3.9 and 4.6 engines. It is impossible to set a carb up properly without monitoring the air/fuel ratios for all the modes of operation of the carb but as a VERY rough guide you will probably find that just swapping out the 65-52 rods for a set of 67-55 rods. You also need to set the idle screws up but you can get them setup by having them set rich at something like 3 turns out, then screw each in 1/4 of a turn at a time, swap from one screw to the other whilst listening to the engine, the revs will start to rise but at some point the revs will drop just a fraction, go out 1/4 turn from this drop off point. Other things that you might need to do are fit the next weaker set of rod springs and possibly larger secondary jets, this is because the smaller engines don't pull as much vacuum whilst cruising which can cause the rods to lift too early, the lack of vacuum wide open throttle can cause the secondaries to not deliver enough fuel which makes the mixture go a bit weak at WOT

[@nathanm3591]

@@sidecarbod1441 Thats some very good advice. I have got it setup fairly well now, no black smoke and reliable performance. It feels a little flat around 2000rpm so i will try changing the springs. My biggest concern is now around venting the motor. I run an-6 fittings on each rocker cover, however i feel this might be too small

[@sidecarbod1441]

@@nathanm3591 I'm not sure where you are based in the world but if you are based in the UK then you might have heard of a company called RPI. They sell Edelbrock carbs and they offer advice on setting them up, the only problem is that they don't have a clue how these carbs work! If you are running their setup which is an 80 jet and 62 52 rod then it is way too lean on cruise, (19% leaner than the out of the box setup on cruse and 21% leaner on the powerstep) the engine will feel flat at small throttle openings. JRV8 is also another supplier of these carbs, his setup of 83 jet 62 52 rod is not lean enough! (4% leaner on cruise). The 86 jet (standard) and 67 55 rods that I suggested you try are 8.3% leaner on cruise and 6.7% leaner on the power step. During my testing I have found that the 3.5 engine will want the carb about 8-10% leaner on cruise than the stock setup. The bigger engines can run with a leaner carb setup because they pull more vacuum, the actual air fuel ratio for the different size engines will be around the same (15-15.5:1 on cruise) but the carb setups differ to obtain this. The piston springs are not going to be the issue for you at 2000 RPM, the springs are a 'load sensitive' part of the carb, at 2000 RPM under very light load (i.e cruising) then the pistons should be in the down position, you will be running on the lean circuit of the primary side of the carb which is the right circuit to be on. You could fit very stiff springs which would lift the pistons but it would be the wrong thing to do! The pistons should lift when the vacuum drops because you are at half throttle, this would mean that you are accelerating using only the primary side of the carb. You would be at 1/2 throttle, the primary side of the carb would be 1/2 open, the secondaries not open at all. What ever vacuum the engine pulls at half throttle (lets say 4 inHg) then you would need the pistons to have lifted, in this case you would fit the springs that lift at 5 inHg). In general teams most engines will need to run similar air fuel ratios (AFR) for different modes of operation but the setup of the carb may need to differ to get these ratios. The ratios below are only a rough guide before anyone 'kicks off'..... Cruise...15-15.5:1 (But basically goes as lean as you can whilst maintaining good throttle response, annular boosters allow a leaner AFR to work). Acceleration....12-12.5:1 Wide open throttle (WOT)...12.8-13:1 Just taking the cruise circuit as an example the 3.5 engines that I have worked on need the carb setup around 8% leaner than the standard setup to get this AFR. Most 4.6 engines that I have worked on need the carb setup about 15-17% leaner than the out of the box setup to get the same cruise AFR. I was running a 86 jet 69-52 rod on the primary side of my carb, now you can not buy this rod, I made mine. If I fitted a 70 thou rod the car was undriveable! I now run my own homemade annular boosters in my 500 carb and the setup so the setup is totally different. The other thing that makes a BIG difference is how your ignition system is setup, really you want the vac canister on the non-timed port of the carb but the big issue is that none of the standard Lucas canisters work very well with the Edelbrock carb. Your timing will probably be something like 4 degrees BTDC without the canister but will need to be at around 14-16 degrees, the canister would add this extra timing. The issue is that lets say your engine pulls 15 InHg at idle, you need a canister that is 'all-in' at 13-14 InHg, the Lucas canisters come in different forms but most are all in at 8-10 InHg, this means that they don't 'back off quickly enough when you open the throttle lets say 1/3-1/2, this means that the timing is over advanced. If you connect the canister to the timed port then you idle timing figure will be way too retarded. (I won't bore with anymore of this but a poor timing setup is in many ways just as bad as a poor carb setup!).

[@nathanm3591]

@@sidecarbod1441 Yes heard of RPI and i'm based in New Zealand. I tried the settings that RPI had listed and it got rid of the black smoke the factory setup was producing. After a years driving I thought i would take another look at the engine and try some different jets so purchased the .067 x.055 rods and refitted the standard jets, however once again the black smoke returned. It was visible through all modes of driving and would have a severe bog if you touched the throttle from idle. So i pulled them back out again. Since then i have added a spacer to the carb as it would take about 10sec of cranking to fire back up after a hot run. I think from here i really need to get myself an air fuel ratio gauge so I can get a better idea of whats really going on. Over here I run it on 91 octane rather than the higher grade, its also probably worth mentioning its the low compression motor and its powering a heavy Land Rover Defender 110. Thanks very much for your detailed replies, at times it can be a struggle getting info on this combination setup.

[@sidecarbod1441]

@@nathanm3591 I'm surprised that the 86 67-55 setup was too rich but if it made black smoke then it must have been! Its worth checking the float height, they are never set correctly at the factory, also go 2mm higher on the float to lower the fuel level 2mm, it helps to get rid of a rich bog when you brake hard. An Air Fuel Ratio gauge is an absolute must when setting any carb up, as is a vac gauge! the fast the you mentioned a AFR gauge means that you do have a good idea with regards to what you are doing! I have a spread sheet that really helps when comparing one setup with another. it is loads better than the Edlebrock chart, if you don't mind posting up an email address I will send it to you along with instructions on how to use it. I also suffered the fuel boiling issue, a spacer is the only way to cure it, I also have a button that I can press to get the electric fuel pump to run even without the engine running, it means that I can prime the carb.

[@obcmissions]

My Edelbrock 1403 on a Ford 289 gave me about 200 miles on 10 gallons when I first installed it. After storing it over the winter it never was the same. It would idle roughly and there were various issues until it was discovered there was a vacuum leak. Now that is resolved and it idles fine as set up by my mechanic, I get barely 100 miles to a 10-gallon tank. Not sure where to start.

[@MuscleCarSolutions]

First things first. Storage on any carb means completely draining it of fuel. If you’re running pump gas, it’s got ethanol in it and with that comes all the crap that fuel attracts. Change your filters. Get a rebuild kit and give it a through cleaning and rebuild. Loss of economy can be a couple things and likely the clean and rebuild will solve some of it. Your next steps are adjusting the calibration spring under the piston that’s attached to the metering rods. You can try it with swapping them out till you find the sweet spot or a vacuum gauge to see what the manifold vacuum looks like while driving.

[@obcmissions]

@@MuscleCarSolutions Thank you, I will try that.

[@bobbydelamar606]

If it's idling and burning your eyes, is that rich?

[@b.m.4066]

If it's gasoline and your eyes are burning from idling, it's running very rich. Methanol and alcohol are a little different but for a regular vehicle, yes

[@bobbydelamar606]

@@b.m.4066 Thank you. My plugs are black also. I'm installing a new carburetor.

[@MuscleCarSolutions]

@bobbydelamar606 not the carburetors fault. Adjust it!

[@bobbydelamar606]

@@MuscleCarSolutions I did several times. It doesn't want to idle. I have to keep the throttle open to keep it running.

[@MuscleCarSolutions]

@@bobbydelamar606 simple adjustments, a good cleaning or check your fuel pressure.

[@raygee1138]

I'm running a pair of Edelbrock Thunder Series carbs (1803 & 1804) on a Pontiac engine. These are part of an Edelbrock top end dual quad kit consisting of the carbs, intake, cam, lifters & rocker arms. I've installed a pair of Edelbrock #8722 1/2" wood spacers under the carbs to alleviate heat soak. The problem I'm trying to overcome is a very rich idle, the tailpipes are black and if I'm in the garage with the car I could die! I've adjusted the float levels to stock and a little less with no difference, if I went too low the car would stall when I made a hard turn or fast stop. The carbs are set up with the as-supplied .086" primary and .077" secondary jets. I'm using a stock mechanical fuel pump and need to check the pressure output-at what point does fuel pressure overcome the needle/seat assembly? Thanks for your time and help.

[@raygee1138]

@@MuscleCarSolutions Copy that-and the good thing about this set-up is the carbs are only 500 cfm each, less than needed for the engine alone, and with 1000 cfm available at WOT there's more than enough for power runs. The car has no drivability issues, well, there's one but that can wait till later to diagnose. I've read that Edelbrock offers spring loaded needle/seat valves to avoid shock encountered by offroad use, maybe they'll help with a lower float level. Also, would you recommend leaving the original float drop setting or changing that as well? Thanks-

[@raygee1138]

@@MuscleCarSolutions I verified that the mechanical fuel pump is supplying a steady 5-6 psi to the carbs. Next step will be to adjust the float levels, do you have a recommendation for how much lower to go than the 7/16" specified by Edelbrock?

[@peteloomis8456]

Ray if your running a very hot cam with a lot of duration i have seen some Edelbrock carburetors run rich at the idle circuit because the vacuum is too low from the cam shaft duration so what do guys do is drill a small hole in each primary throttle plate to allow more air to come through at idle circuit idle ! Had a guy at the shop i worked with that had this problem on a 70 440 Challenger that was doing the very same thing because he had this radical high duration cam shaft and with small incremental changes on the hole fixed drilled in those front throttle plates he was able to get it running much better to a point it not only pulled harder out of the hole it also wouldn't burn your eyes at idle in the shop anymore . He tried lowering the floats as well as leaning up the primary jets but that still didn't do much until the holes were drilled !

[@barneywarwick1038]

i have a 93 dodge Dakota with the 318 it's fule injection now how can i get more horsepower out of fule injection if i switch over to carboraitor i was told go with the holly 600cfm 4bbl electric choke and the air gap intake and a return line fule pump regulator the transmission is ran by the computer can i keep the transmission

[@garystump1776]

I very much enjoyed your information, just got an old plymouth with 318 with edelbrock 1405 ( and year built carb 0462 how do I read what year this is

[@markthomas9273]

It amazes how many people out there refuse to understand how these carbs actually work!! And like other carbs, label them junk and write a bad review on them.

[@suejackson8007]

I have watched this and some other of his videos. i have a 66 Mustang, slightly warmed over 289. My old Edelbrock1406 was just changed out to a 1906 AVS2. I replaced the fuel pump that was rated between 6-8 psi. New fuel hose and filter between the pump and carb. As recommended, I added a regulator. [A cheap one at first] No matter what adjustment I made, all I got was between 3-4 psi. So I upgraded to a more expensive regulator, and still only reads between 3-4 psi. His channel says Edelbrock's like a 5-6 psi reading. Help

[@MuscleCarSolutions]

@@suejackson8007 well it’s time to verify what pressure (flow) the pump is actually producing. Then determine if the pump is defective or you have something in the system blocking the flow.

[@triplecranks9540]

I used to be (lol) pretty good with Quadrajet carb tuning. Using a lambda meter I could get them to run like fuel injection. I have since placed my focus on tuning fuel injection. Kind of ironic. My question is I am helping a gentleman tune his newly installed Edelbrock carb. Same one you have featured here. We have no idea of the cam in the car. From my experience and the way the car is setup (all out drag setup), I assume the cam is a "bottom of the page" cam. Either way it is very radical. Lots of overlap. I am trying to control the idle. In gear the car wants to stall. If it were a Quadrajet I would simply start with drilling a small hole in the throttle blade to help keep the blade in the area of the transfer port. I have a feeling with the idle screw set so high it is feeding off of the main jets too much. The idle screws are doing squat. Is it advisable or OK to make the same modification of drilling the throttle blades with this carb. Thanks for a great explanation. I subscribed.

[@crazyhorseDOC59]

I'm using anf AFR gauge running a 650 AVS2, in cruise mode running 13.5 throughtout the RPM range up tp 6000, however if I go wide open throttle after about 3000 RPM the AFR goes to 25 or more...way to lean. When I go richer on the primary side it runs 8.0 to 10. without any change at WOT, still runs lean. went richer with the seconday jet...no change in WOT Engine is a SBC 350 has about 3000 miles.

[@MuscleCarSolutions]

How have you adjusted the AVS?

[@crazyhorseDOC59]

@@MuscleCarSolutions currently at 7 for model 1915 on pink spring .104 secondary jets, minus 1/4 turn less tension on the secondary plate.

[@MuscleCarSolutions]

@@crazyhorseDOC59 there we go. Add tension to the AVS. kzbin.info/www/bejne/nqPalJijmtxrnZo

[@crazyhorseDOC59]

@@MuscleCarSolutions that was the only video of yours I had not seen. All your videos are very well done. Great productions. Thank you.

[@MuscleCarSolutions]

@@crazyhorseDOC59 glad they have been helpful! Let me know if that AVS adjustment helped.

[@timthemechanix]

Working on one that didn't come with the book, don't know if the jets are original. It's a 1406. It's been through a few mechanics because when I changed the trans with a rebuild I found when getting a rebuild torque converter it had a Buick converter in a '80 Monte Carlo 305(?) turbo 350 trans. Owner took it to another shop because of hard starting, plugs cap, wires replaced. It hadn't started in months, hooked up the jump box and I just pushed the choke down a hair and it fired. When it got here I through a timing light on it after finding the marks. Couldn't see them they were so far off. Factory says 4 degree but considering Denver is 5,000' elevation I've learned to add 8. So I retarded it probably 10 because I couldn't even see the mark, to get to 12. Everything changed after that, almost. Fist touch of the key it fires up whether it's 10 degrees or 60 outside. And when it's still cold acceleration from a dead stop is fine. But at operation temp it want to dog out if I punch the accelerator quick from a stop. I have had dozens of these carbs over the years and worked on other cars with them, never had a problem. This owner was ready to spend a fortune on fuel injection until I adjusted the timing. But next comes the digital dashboard because I need to know temp, oil pressure, rpm and that it's charging. And he wants it and brought it today. Thanks for the vid, gonna check out accelerator pump first.

[@timthemechanix]

@@MuscleCarSolutions Cool, appreciate it. Been wrenching allot of years. Fuel injection was still fairly new, disk brakes weren't standard equipment, and computers weren't used yet. Damn, even electronic ignition systems were just coming in. My first real job was working on police cars as a mechanics helper in 1976 at Spokane City Garage and I'd just rebuilt my first engine, a 421 tri-power in a '63 Grand Prix, my first car. And all this hi-tech diagnostic stuff I have accumulated is about useless without a sensor to read... Again thanks.

[@stjp6599]

Hello, eddie carb 600 on 72 Dodge Challenger 340. Starts great cold. Idles great when kickdown.Take off get to first light when at temp,always have to give slight bump to pedal to lower idle. Thoughts?

[@MuscleCarSolutions]

Linkage adjustment? Electric choke? Not releasing? Fast idle cam sticking?

[@guillermocastillo3833]

This was a great, informative video. Thanks!

[@MuscleCarSolutions]

I’m glad you liked it. I’ve also broken down each topic with a separate video of you want more info. They’re all in my Edelbrock Carb Tech playlist.

[@chuckchrystak4397]

Great video, nice and straight forward!

[@MuscleCarSolutions]

Thanks!

[@arcorob]

Great video but confused on the front vacuum ports (around 7:30 in the video) . I have a 1966 mustang, Edelbrock Performer Manifold and carb, original style vacuum advance distributor. I was under the impression that the right (drivers side) is what I should use and the left was for type that have egr. Am I wrong? I also notice with a vacuum gauge, left port is Zero unless throttle is applied whereas right port has constant vacuum. HELP ..LOL... I want it to be hooked up correctly. Thanks !!!

[@arcorob]

Bone Head yup I knew that and thanks for straightening this out. But now begs the question of vacuum gage and setting idle air fuel. I have seen you should get max vacuum when setting, then back down 1/2 turn on each side. How do I get max vacuum if it's zero at idle? Use the other side?

[@arcorob]

@@MuscleCarSolutionsYou are awesome...thanks for the quick clear replies !!!

[@Washitguy]

So, because I am dummy... which port to use when using a vacuum gauge? Driver or passenger side?

[@sed6]

@@Washitguy Driver side for running a vacuum gauge.

[@andrewbutton5580]

On a cammed 350.chevy with a tunnel.ram.what should the primary jets be ? Should the springs be lighter if the cam is large ?

[@willemtheron]

If the step-up springs do not fix a hesitation, stumble etc. and you go on to change the metering rods, do I need to go back to the first spring that was in there before I started changing to different springs?

[@MuscleCarSolutions]

That’s the difficulty con tuning by just feel. An AFR would let you know if those changes were effective before you move on to working else. Keep the springs you selected, then make your rod/jet change and see if it gets better.

[@tommychest6159]

A great video indeed! I am about to buy a buick with a 455 engine with an edelbrock and and at cold start it is has a hunting idle, also when you hit the gas it does not pick up well, seems like it is out of power. This information might be a little general but do you have any idea what might be the problem? It it just a matter of tuning the carb or is it a more serious problem? What might be the steps to undertake? Greetings from Holland

[@tommychest6159]

@@MuscleCarSolutions Thanks for the quick response. I will try to obtain more information to narrow it down and then I would like to come back to it. Thanks alot, I apreciate it!

[@TheHomy70]

Black sparks plugs & poor gas mileage mean too rich...use the chart to change metering rods only? Or would a change in Jet size too be needed?

[@ciaranlowe5547]

Excellent video thank you so much for sharing your knowledge. I have one question, I’ve built a Windsor 351 60 thou over AFR heads and Edlebrook AVS2 800cfm carb and manifold. The engine is not installed yet. Is 800 cfm too big . If it is, can I adjust the carb downwards ?

[@MuscleCarSolutions]

You can’t change the CFM of a carburetor. What is the max rpm on this engine?

[@ciaranlowe5547]

@@MuscleCarSolutions street use only

[@MuscleCarSolutions]

@@ciaranlowe5547 need an rpm. What’s the cam rated for? What range? It’s important.

[@ciaranlowe5547]

@@MuscleCarSolutions 1500 to 5000 rpm range using a Lunati roller cam 112 lobe separation 108 center line rolle rockers 1.6 ratio. Cam part # 20350711. Hope this helps

[@MuscleCarSolutions]

@@ciaranlowe5547 yup. That’s exactly what you need to know. By the math, that engine would need a CFM of around 523.72. If it’s just a street cruiser with a really low rpm range, you’ll have a way easier time tuning with a 650 or 500. That 800 will be an extremely rich running engine that you won’t be able to tune away.

[@bubbastrahan87]

I'm trying to troubleshoot a problem with my 1406 edelbrock. At idle, the engine runs fine, and revs up fine, but when I put it in gear to drive and press the gas, it doesn't respond and lugs the engine down. It doesn't die, but I can floor the pedal and engine doesn't increase RPM. Ever heard of that issue? or think that is something else than the carb? I can't find any good information about the problem I'm having.

[@bubbastrahan87]

@@MuscleCarSolutions ended up getting another carb to try and truck runs fine now. So its narrowed down to something wrong with that carburetor internally. Haven't torn into it yet to find out the problem

[@serialgrillaz6669]

I have owned a carb for all of one week now and have a wideband gauge, its reading well into the 10s at wide open throttle, 4th gear 80kph is there a way to accurately calculate what secondary yet i would need rather than going down in increments? The episodes are great btw. Half way through allready

[@MuscleCarSolutions]

Always take small steps. As you've figured out, 10 is WAY too RICH! Yikes! Its the quicker way to tune is to take those small steps. It all really depends on the size carb and what the engine is. You can check out my video on what size carb to run for a simple equation plus some additional tips at the end on how to pick a size. Might be useful to determine if what you have is going to be your best option. Dont hesitate to ask any questions. Always glad to help.

[@serialgrillaz6669]

@@MuscleCarSolutions thats another thing thats throwing me off, its a 350 602 (circle track motor) it makes 350 crank, I would think the 600cfm edelbrock would be pretty close from factory. It has been sat for 3-4 years though

[@rodshuffy4045]

Just wondering, I always hear make sure timing is right. Well how do I know that? Im at 7000 feet elevation and my engine will not under any circumstances run correctly at factory timing specs. So carb is rich....duh 7000 ft. Plugs black with carbon so can't read them for timing. Suggestions? Right now I'm at 22 deg BTDC at idle in N and in Park. 38 deg advanced at wot with 12 deg vac advance. Is that close enough to be "right" Im setting carb idle speed per the "square" transition slot and adjusting timing to get needed RPM at idle. Is that correct?

[@jonjacobsen6339]

I have a Ford 302 crate motor and just installed an Edlebrock AVS2 1916 Off-road carb. I believe this motor has around 300 hp, but not exactly sure. I'm getting a stumble sometimes off idle. I have tried all 3 adjustments on the accelerator pump location & found it runs better on the leaner setting. However, I am still getting a stumble. The extent of the stumble varies from none, to somewhat significant. Where do you recommend I go from here? Thank you,

[@MuscleCarSolutions]

Ok that’s good. Now you know it needs to be leaned out. Get a calibration kit and you can start making adjustments. Step up springs first. Then you can start on the tuning chart.

[@davidkeeton6716]

The manual I have with my 1413 800 cfm carb says that the passenger side small port is for emissions controlled engines and the driver side port is for non emissions controlled engines/distributors. Right now I'm actually using the original 1964 point distributor. Should I use the one on the driver side, that I am using?

[@MuscleCarSolutions]

The better question would be how big is the cam profile? Is it stock? Use the timed port. Is it an aggressive long duration cam? Use the full manifold port.

[@m.pietro9087]

Nice video. Once you mentioned I have a question. My car is running great, it idles perfect, at wot is good, part throttle is good as well. Off idle is good as long as I give like 20% of throttle or more, however if give only a tiny gas, like 10% of throttle in order to leave a stop sign slowly there is an hesitation, pretty bad, I’d say. Other than that, like if I’m driving like at 30 mph or more, it is crisp. Any recommendation?

[@m.pietro9087]

Bone Head first of all thank you for your prompt reply. I’ll start by the accelerator pump. I’ll have a vacuum gauge hooked up to check it. Thank you. Happy Thanksgiving!!

[@danielmather8037]

Thank you for your amazing content!!!

[@kevinsweetwater7293]

This video is awesome! Thanks

[@YuckFou502]

Hello I have a 600cfm Edelbrock on a mildly built 305. It used to scream it's ass off and squeal the tires going into second with a turbo 350 tranny with the Rochester carb I had that crapped out (no clue what size it was). I wouldn't be surprised if I replaced it with too big of an Edelbrock based on advice from the poop head mechanic I had put it on (I was just a boy, mkay?). My question is whether I can tune the 600cfm down enough to handle my little v8 or am I better off switching to a smaller size to get it back to squealing like a pig? (but hell I don't know, maybe I could tune up? No clue)

[@driftking4134]

Hey bro thanks alot amazing explanation, i appreciate...

[@sandalsinak6829]

This is more than likely a stupid question but I just purchase the AVS 2 ( 1906 ) for my 72 k2500. I looked up the calibration chart you had mentioned but there is no graph for the 1906. It only goes to the 1825 and 1826. Is there a graph for the AVS2 1906? if so could you lead me in the right direction. This video answered so many questions, thank you for your time sharing the knowledge.

[@MuscleCarSolutions]

If you go to the Edelbrock site and search the 1906 you’ll find the pdf instructions link on that landing page. You’ll need to scroll down 3/4 of the way and you’ll see the tuning chart for the 1906. Please don’t hesitate to ask me any questions. Always glad to help!

[@sandalsinak6829]

@@MuscleCarSolutions You are awesome! I found it. There is so much information on there. I am currently on the oil fields in alaska. When I was home last week my holly started giving me issues. I have never really figured out how to properly tune it. So i decided to buy the AVS2. I am really excited to put it in. I just hope I can dial it in nice. I just rebuild my transfer case so I am hoping I can do this :) Thanks again for the help my 72 k2500 I hope starts running a lot smoother. It has the 383 in it also.Thanks again. Is there a way I can contact you if I have any questions? I don't wanna bother you though but Im sure I will need some clarification when I dive into this. Take care and thanks again.

[@MuscleCarSolutions]

Just drop me a note here and I’ll be glad to help! Best of luck to you. If you tackled the transfer case, you’ll get the carb dialed in no problem. You can also check out the other Edelbrock tuning videos in have in a playlist. Might give you some more tips and insight on your tuning.

[@sandalsinak6829]

@@MuscleCarSolutions Thank you sir!!

[@garrettgrantham7411]

Thank you great video. Got a 650 cfm avs2 for a 302 Ford 1969. Running crazy rich, I believe I'm oversized on the carb. is it possible to detune (jet/rod change) this 650 to run on a small block 302 Ford?

[@MuscleCarSolutions]

Unfortunately you can’t tune CFM. I would agree you’re probably are too big on the carb. Not much you can do. Lean it out where you can and live with the rich condition. Or make the switch to a 500.

[@richardalbano523]

I was curious about my 1406 she was running great with choke closed then after 1 test ride she started running like dog crap, surging and hard to keep idle in gear. If i cover the butterfly with my hands the idle raises and smooths right out. Sprayed carb cleaner around the top plate gasket by the throttle and you can hear and see the difference on the vacuum guage my question really is this a normal occurrence on these carbs? Thing is only a few months old has no miles on it. Thanks for the videos and the help

[@MuscleCarSolutions]

You have a vacuum leak somewhere.

[@larrylewis2674]

Great video!! I have a couple questions. I have a 38 Ford 2 door coupe with a 327 SBC and an Edelbrock AVS2 650. Since I got the car about 4 months ago. I bought the AVS carb, HEI distributor, spark plugs and spark plug wires, new standard fuel filter set up. I also have an in tank fuel pump, but want to change it as it is leaking at the gasket every time I fill it with gas and smells through the trunk. I have a slight hesitation at cruising speed. If holding a speed above idle it will slightly hesitate (not every time) until I accelerate some more. I bought the calibration kit and was hoping to send you a photo of the chart to make sure I am reading it right. So questions..any thoughts of what is causing the hesitation? Also, I am planning to use your suggestions on filter set up. Can you recommend Micron filters and a regulator. I am thinking of eliminating the in tank pump and going with an in-line pump. Any recommendations on a fuel pump. Not sure if I can send the calibration chart via photo on FB. Do you have an email that you would share?? Thanks!

[@larrylewis2674]

I know the tranny is a turbo 350, all I now about the cam is whats on the original build list from the late 90's that it's "aggressive", balanced/bored 40 over, and a Holley high rise aluminum manifold, I don't now the compression ... I can check with the mechanic who has helped with the upgrades? I have the calibration chart and if I'm reading it correctly the closest reference number moving to the right and up in "Rich in Cruise Mode" is "11" #1430 jet and #1455" Metering Rod. Just not sure if that's how I should be reading the chart though? Thanks for your help!

[@jimmyjamesbbq]

When tuning dual quads do you tune then the same? Progressive linkage. Like if I do a metering rod change for cruise do I also use the same number rod for the second carb? 355 avs2 500’s. Running rich at cruise and real rich at WOT. Thanks.

[@MuscleCarSolutions]

You’re always going to fight a rich condition. You’re way over carbureted. So just get used to that and all the things that will come with it. Lots of oil changes, spark plug changes and a little more time tuning as conditions change. No they don’t get tuned the same. Progressive linkage is the right way to go. Generally I’ll lean the secondary carb out as far as I can. Run as much as I can off the primary, if that is how your linkage is set up. Some run off the secondary carb and the primary is only used at WOT. In which case I lean out the primary. There’s a problem with all that. You cant change CFM. You’ll still be flowing that amount of air and the air movement through the venturi is what signals the metering circuits to provide fuel. All you can do is try to lessen the fuel but the signal will continue to be there and continue to fight you.

[@tonyvermeer7409]

I have a 1406. When adjusting the fuel regulator, do you set it for the MAX it will allow? I have mine set at 5.5 lbs. when it is at high idle. After I drive it then check it again, it drops to between 3-4.

[@MuscleCarSolutions]

I always start at 6 at idle and tune down from there as needed. I’d you’re dropping that much pressure, it’s likely one or more issues. Fuel lines too close to a heat source. You’re using a deadhead style regulator and they are famous for dropping some pressure. Put a clear filter before and after the regulator and see what the difference looks like. Once you get it sorted out, remove the filter after the regulator. We’re not a fan of one there. 😉

[@badthingsauto666]

just baught a brand new one the four barrels will not open unless i open them by hand...... I hate that sob and am ready to put my quadra jet back one any tips?

[@wayneking3408]

A question regarding AFR readings, 4106 carb in 1978 chev 350, when running down the highway @ 60 mph, my AFR is showing 14.0 -14.3, when I come to a hill it drops to 10.5 - 12.5 and the secondary has not cut in, are these numbers normal? I would like to see the up hill numbers higher to save fuel

[@MuscleCarSolutions]

@@wayneking3408 when you come to a hill you’re under load as the vacuum drops in the engine and meters more fuel. Go back to your calibration kit and follow the chart to go a little leaner. 14:1 is ok. Not optimal, but ok. Anything leaner than that you’re asking for bigger issues.

[@CLINTSTER77COX]

Great video! You said we could leave a. Question in the comments. We put a new 1805 thunder on a 305 small block . At launch with foot brake it stalls ? Any idea where to start . Any comments appreciated. Ty

[@CLINTSTER77COX]

Bone Head sorry 1805 I believe. 650 thunder with manual choke

[@CLINTSTER77COX]

Bone Head the Edlebrock chart said down to 283 . We have headers and performer intake with power glide , 4.56 9 inch ford . Stall is 1800 I think . Can we lock out the secondary somehow? Just to give it a try ?

[@CLINTSTER77COX]

Bone Head electric water pump and fans but as far as the core components stock except zero emissions and msd multi spark box

[@CLINTSTER77COX]

Bone Head man I thank ya . It’s been on the car for over a year . My dad is an old timer and spent 20 years building this bracket car and went to the track for the first time and died on the line . It started right back up and did 75 mph in the 8th mile . You gave us somewhere to start . I think the original idea was to stick a 383 in there and swap everything over so we don’t have to buy anything twice but not having anything to start with . I guess I could put a 75 shot nitrous on a one second timer at launch and still stay budget friendly. Thanks

[@CLINTSTER77COX]

Bone Head here’s the chart Your right because it’s not talking about a stock 305 . advertising.edelbrock.com/Literature/Misc/EDL_Carb_Application_Chart_03186.pdf

[@TheTexasDuke]

Hey so just recently inherited my fathers red 1983 gmc shortbed he’s passed sadly, so I tuned my new carb but ya keeps flooding on just giving it gas and putters out, then I have to wait 30 mins to retry and move it

[@MuscleCarSolutions]

Lots of things to look at. If it’s blowing past the needle and seats then figure out why. Get a pressure regulator and dial the pressure to 6psi or lower. Take the top off the carb and see how much garbage is on there and clean as necessary.

[@PSmolchek]

GREAT VIDEO - quick question. Just dropped a crate motor in my '67 Camaro - car sat for about 6-8 months while I was working through pulling the engine apart and deciding what to do. When I put the new motor in, I didn't rebuild the carb at first until about 60 miles into the rebuild the car just didn't seem to be running right. Lagging, no strong pickup. So I pulled the carb, disassembled and did a cleanup on it, replacing the gaskets but keeping the jets. Replaced the small needles in the float assembly. Car is running but just doesn't seem to have that punch I expected - and also, after the rebuild, when I am on full throttle around 60-70 mph and I let off the throttle, it 'stays' - pedal doesn't stick, but the engine RPM's really don't drop like they should until I 'pop' the throttle and then she drops like normal. What part internally did I not check or install correctly that would be allowing that to happen? THANKS.

[@MuscleCarSolutions]

I’ll start by assuming your ignition system is in good shape and working properly. What is your total timing set at and what RPM does it go to full advance? Ok so just like the video, how is your fuel system set up? What is you’re pressure regulator set at? Where is your accelerator pump set at? Stock middle hole or did you add more fuel or leave it alone? As far as the not dropping in RPM when you let off the gas, that’s going to be a throttle return spring issue. What are you running there?

[@PSmolchek]

@@MuscleCarSolutions THANK YOU! Appreciate the quick response. To your questions: 1. Yes, ignition system working properly. Car starts and runs normally. Voltage at the coil is 11.98. 2. Timing: was set at 10deg TDC at 650 rpm per the instructions with the crate motor from GM Perf with vacuum advance off. This theoretically should produce 32deg of total advance at WOT. 3. Fuel system: I took notes. I have a single SS filter AFTER the pump. Do not have a pressure regulator. Car didn't have one and ran for three years. Assumed pressure was 'good' but now I will look at putting an inline regulator. 4. Stock middle hole on the accelerator pump. 5. Throttle spring - running the standard spring that was on the car already. Has plenty of 'pull' to it so I don't know why its not responding. When the hood is open and the engine is running, I can hit and hold the throttle and when I release it drops as normal. Seems to be on load and north of 60mph when it sticks. THANK you again for the information. I downloaded and am reading the Edelbrock manual for the 1406 today to learn more.

[@MuscleCarSolutions]

I would verify when your all in advance hits. What RPM. A common mistake is thinking that because something ran well before then the additional tuning points or support isn’t needed. For sure get a regulator and a gauge. Keep an eye on the pressure from time to time. It will change over time on a mechanical pump and you’ll need to adjust. Set the accelerator pump on the one closest to the pivot. That’s the smallest shot of fuel. See how it responds. If it’s worse, go to the furthest one to give it the biggest shot of fuel. See if it’s better or worse. I’d verify the timing first. Then adjust the accelerator pump. That’s the free stuff. But I’d get a regulator and a gauge and get it installed. Set at 6psi initially. You can adjust down lower later as you tune. Question on fuel. Running E10 I’m assuming? Not E85? Or blessed enough to use non ethanol fuel?