EPISODE 103 Tuning Classic Car with Vacuum Gauge, Plug Reading, Jetting Autorestomod

Home page: www.autorestomod.com
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This week we use a vacuum gauge to fine tune our 1965 Mustang hardtop, how to read your plugs to know if the carburetor you are running is too lean or too rich. We also show what the exhaust should sound like at the tail pipes and how to use the spark plug wire removal test to find dead cylinders. We also give tips on how to test your car so that your changes will compare well with past test.
Thanks for watching!
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[@redneck048]

Thanks for the video. I been working on my 1974 dodge van and your tips helped me to get it running a bit smoother.

[@KLsuperspeed]

Great comprehensive video for someone that is just learning older style carb and distributor tuning.

[@elniteo]

THANKS ! This Vacuum Gauge tuning ,solved all my idling, stalling and misfiring problems ! My 64 Fairlane 260ci engine with Holley carb. was running on 15inHg. tuned all to 20inHg and all problems solved. The Fairlane pulls incredible now, gas-milage has extreme improved and idles very happy.

[@pedrosilvaslva2625]

you tunned your engine but what your engine problem was?

[@LandonRoy-cv9rt]

Y’all explain this better then anyone else

[@brianochs2548]

Great video on setting up a carburetor with a vacuum gauge . I on my way to get one now . 👍🏼👍🏼

[@gratmaleezie]

This is hands down the best video on how to use a vacuum gauge I have found on KZbin! Thanks for the great video, going to apply it to my Motorcraft 2150 on a 79 CJ7 I bought recently. I am new to carbs and this is a huge help. Gotta say though, while the information is terrific... Mr.Fords makeup did it for me.

[@donrutter6765]

G M kzbin.info/www/bejne/gHWzqIxmgceFjLs

[@AutoRestoMod]

Thanks for the kind words Pavel! We're planning to delve into the Fox bodies '79-'93 Mustangs very soon. We can only imagine the trials you must face doing an American car in the Czech Republic...

[@AutoRestoMod]

Good point. That is where the drive comes in. You may need to back off of the timing a bit. We may hit that one in a future episode Mike! We appreciate you bringing it up!

[@uperbee]

Glad you guys put this get there. Subscribed because l learned much to use on my new old 66 Impala I just got for my 64th Bday. Great content n well done.

[@lynndempsey4096]

I would kill who ever gave me a piece of shit Chevy!!!

[@blahblahblahblah2837]

Very comprehensive and well explained, thanks. Subscribed!

[@pavelprunner5009]

Hi guys, I've already seen all your episodes. It's one of the best channels on youtube. Lot to learn :) and I can use many of your tips on my 1984 Ford Capri 2,3l V6. Greetings from Prague, Czech Republic and keep on doing those great videos. Thanks, Pavel

[@MrErikw26]

Just a couple of regular guys, and that is why I watch, no paid professionals following a scripted routine, NORMAL guys youd find in their garage in Anytown USA working on classic cars.

[@jmarco4331]

Stumbled on your video. Thanks for posting the very useful info. I plan to try these tips on my big block 70 Chevelle .It’s a carbon footprint nightmare. My wife hates to ride in it because we always smell like fuel after going for a ride

[@jimmywilson1388]

Thanks for the information… I was born in 83 so I know more about fuel injection but I recently bought a 72 F100 because I’ve wanted a bump side since I was a teenager. I’m soaking up this information like a sponge…😄

[@Naitrio]

Its pretty amazing what a vacuum gauge can tell you with an old car, or any car for that matter.

[@alpineplay2944]

Thank you! Learned a lot off this video and was fun to watch

[@jakekurland3568]

This is absolutely amazing.

[@AutoRestoMod]

Depends on what you are tuning. Unplugged it can help you set the initial timing. plugged in you can set idle mixture and check the vacuum drop under acceleration.

[@AutoRestoMod]

When the car is running badly after all the things we've shown you that is a good indication. If it is running rich (black smoke from the tailpipe) that is also a good time to go in and work on the carb.

[@jevchance]

Great video guys, thanks. I learned a lot, and it'll come in handy for me down the road. If I ever get down to SC I'm bringing beer.

[@samhicks97]

This video had some valuable information, thanks.

[@AutoRestoMod]

Usually it will be around 1 to 1.5 turns of the idle mixture screws. You might also check for vacuum leaks around the carburetor base. If you are still having problems contact us on our web site and we'll see what we can do.

[@2541968joey]

Running air/fuel ratio gages on my XKE, helps to tune the 3 SU HD8 carbs for power

[@AutoRestoMod]

Yes, these things will work on any carbureted engine.

[@AutoRestoMod]

Sounds good! Vinnie will be happy to know that we have another 3rd Gen Camaro/Firebird owner!

[@reijerlincoln]

Cool video. I've been learning a lot lately.

[@neilray8416]

Thanks for the great video. You are awesome!

[@coreybell9525]

i am new to tuning and building. i have EVERYTHING you recommend. just no knowledge of what im looking for other then a smoother sound. thanks for the info. good video edit: after watching this and a few other videos i went out and hooked up my vacuum gauge and was at 5. i twisted the distributor as far as i could and brought it up to 17, i think im off a tooth, but i also have a large (not some hog ass race cam though) cam, a comp 268xfi. so 17 may be as much as she wants but it definitely sounds WAY BETTER also readjusted the idle screws on my oversized demon 750 and it does not smell nearly as rich. thanks man great video

[@AutoRestoMod]

Go look at our timing video too: kzbin.info/www/bejne/h6vClIyFmpd1aJI

[@AutoRestoMod]

If your pump is maintaining the recommended pressure for the carburetor (Edelbrock says no more than 6.5 psi at the carburetor). First look to vacuum on the distributor, if the ported vacuum is not hooked up get that working and make sure that the vacuum can on your distributor is the correct one for your application. From there if the problem persist look to your metering set up.

[@irocn2010]

Thank you guys so much!! I wish I knew where u guys have ur shop at to personally shake ur hand!! Great teachers.. I'm just a troubled 25 year old trying to revive my dream cars!! I have the 87 Trans am 5.0 and a 88 firebird 5.7 which both need alot of work so ull hear from me more...

[@chicagothunder1guesswho868]

Try using the vacuum gage rolling in high gear @ 40 mph adjust the timing to the highest setting after you have done what you did. The movement that you make by turning the distributor will be ever so slight a 1/64 at a time. You can only do this with a tiny hammer, I like to use one that I made from a 3/4 inch brass bar stock an inch and a half long. You just let the weight of the hammer touch the vacuum chamber while the hold down bolt is snug but not tight. Vans are easy because you don't need to stop and get out. It does not matter if the engine is computer controlled or not because what you are doing is increasing the range of advance. Every engine is different because of machining and the condition of the timing chain. You get the best performance and mpg by setting the timing this way. Sometimes you have to back it off a bit because of a slight ping but that depends on the fuel you're burning and how fast the curve on the distributor advance is. This is what I learned running a chassis dyno back in the day but you can do it on the street too it just takes a little more time. The video was entertaining and you got everything right but you have to know how critical a tiny tap to the rotation of the the distributor really is it could mean a couple of miles per gallon and I'm not kidding have fun and keep on doing the videos good job!

[@AutoRestoMod]

best place is the vacuum tree on the intake. That is a "neutral" vacuum source (pulling form the total vacuum of the intake). If there is no tree, find a single port plug that will fit that threaded opening and use it to establish the vacuum.

[@AutoRestoMod]

True. The larger the cam the worse your vacuum signal. But even in those instances a Vacuum gauge can still help you out with figuring out what power valve to run. Note that we like vacuum advance for street engines or mild performance engines. If it is so radical that the signal is below 10 inches of vacuum no matter what you do then you are going to have to apply a whole new set of rules.

[@evilokc]

hey guys thanks for the video. I enjoyed it. I just started tuning my carb with a vacuum gauge and this video helped a lot. I was able to raise my vacuum from 14hg and idling like crap to 21hg with a beautiful smooth idle. I have a question about the timing adjustment with the vacuum gauge. 1) are you still using manifold constant vacuum? 2) did you unhook the vacuum advance?

[@AutoRestoMod]

There should be a vacuum tree on the intake. Use one of the smaller vacuum ports to test from.

[@Redmist.65]

thanks, this is the answer I have been looking for!

[@kgroombr]

Just finished doing this with my Chevy Vega. A bit easier as there is only one idle screw on the 2BBL, but it runs great. Thanks!

[@train4905]

Absolutely superb sir .

[@AutoRestoMod]

Thanks!

[@taylormach1699]

Learned alot, thanks.

[@AutoRestoMod]

We'd recommend getting into some howto videos. Check out Miller Welders and see what they have. Eastwood also offers how-to videos on welding. Best thing to do is to get the basic knowledge and start out on sheet metal (salvage yard stuff is great if you have a You-Pull-It yard around, fenders are usually less than $40. Cheaper than sheet steel.

[@AutoRestoMod]

Depends Barry, most of the suspension will work. power brake boosters won't. spindles will. Brakes are the same. No sheet metal any where on the car will bolt up. You might use the floor pans BUT there will be heavy mods. Check Autokrafters, they have a Maverick catalog that will show what is available.

[@TheVitusGarageAutoblog]

Your videos are a great help

[@AutoRestoMod]

Thanks for the kind words!

[@DJDevon3]

Don't know about these old classics but most vehicles have a plastic grommet on the firewall to where you can run wires or vacuum hoses into the cabin that way completely bypassing the possibility of the hood crimping the vacuum hose. So what if you have to use 10 or more feet of vacuum hose the readings will be the same no matter the length. Great video on the importance of good vacuum and base idle!

[@AutoRestoMod]

Good point DJ.

[@MrErikw26]

Drill and weather strip with some seam sealer, instant custom hole in the firewall

[@AutoRestoMod]

You might check for vacuum leaks. If a Holley won't change vacuum and doesn't start to stumble with the mixture screws in, it may be a vacuum issue. Get that worked out and then start tuning.

[@AutoRestoMod]

We'd check the wiring to make sure that the firing order is correct. Go to our web page and contact us and we can send you an image of the firing order to help you out.

[@charleysgarage]

YES! I like it. Doing it right, great job

[@AutoRestoMod]

Thanks for the kind words.

[@garyfain7235]

Great video!learned a lot! So, question for you guys. Have a 65 TBird, 390 CI diagnosed with bad carb. Replaced with a Holley 600. Engine idle is a little rough, with a little flat spot accelerating. Also, hard to start after running to normal temp. Runs well otherwise. Any thoughts? Love your channel. Wish you were near cause I’d definitely come see you for a tune up (which it had less than a hundred miles ago…by a professional 😊) Thanks and keep up the excellent videos

[@darrenjosey5616]

Just learning so much from this channel! Hi again, I just did my first vacuum tune on my 71 Lincoln Mark III (its got the Motorcraft 4300 on it). Upon starting the car fires right up and idles smooth until I tap the gas to begin driving and the choke opens then it idles rough. Sitting at the stop sign at the end of my street I can feel the whole car shaking. After 10 minutes of driving sitting at a stop sign/red light, no more rough idle. Made sure the car was warm, setup the vacuum gauge and its at 20.5/21 inches of vacuum at factory idle mixture screw settings and even with the screws all the way in or all the way out I'm at the same measurement with no change but needle dances more than what the good tune you showed in the video. I do however notice my fuel pressure gauge is bouncing from 6 to 7psi at any idle mixture screw setting. Something other than the carb is the issue?

[@tamapisisamipeau6343]

Thanks very helpful

[@ronniebuicks5569]

One of the best shows on u-tube. RIP POPS

[@AutoRestoMod]

Thanks for the kind words! Miss my dad just about every day. Find myself sounding like him with the kids...too funny.

[@irocn2010]

I need to learn how to weld! Need your tutoring please and thank you! Both my cars need body work. Quarter panels and floors need to be redone, living in Chicago Illinois suck because of the snow and salt.

[@AutoRestoMod]

It sounds like the new carburetor is running too "fat" if it is flooding. You'll most likely have to play with the metering rods. We recommend checking into some tuning guides for the Edelbrock. Also, make sure that you check your set up with the vacuum gauge. youo should have between 15 and 20 inches of vacuum at idle. Private Message us if you have any more questions.

[@KayakTN]

I'm looking forward to using this on my Fairlane. It's been sitting for a while so I could work on my other projects. The car never ran right after I replaced the points last year and continues to overheat.

[@chevyelcamino1969]

+KayakTN on my 1969 El Camino I was having slight overheating issues for awhile and found out that my timing was a little off which had the spark detonating a little late and partially dry firing in the cylinder causing the cylinder wall to be higher in temp increasing my coolant temp by about 20 degrees! Hope you get your girl on the road cruising soon!

[@fluffykittynoodles]

Sweet, thanks guys. Yeah, Vinnie mentioned it once or twice. He was real insisting about it, now that I think about it...

[@lkkjhtemmexv1838]

great car

[@adddad9779]

Bring back Gramps!!! He's the man!! I mean you guys rock too with the solid info and stuff, but bring him back!!!

[@AutoRestoMod]

Sadly, pops passed away last year in November. I miss him every day.

[@adddad9779]

AutoRestoMod Muscle Car Resto and Modifications my respects for the loss.... thanks for making your show. I have learned a great deal for them.

[@itruns]

Low vaccum, then do you close the idle mixture screw in more to restrict air?

[@MrJayo73]

I use a vacuum gauge because my timing pointer isn't the correct one but anyways I can get nice high vacuum reading. I shut it off and start in it and my starter labors so I have to back it off and any reason for this. 82 c10 305, lunati cam with 218 duration, edelbrock 1406, new distributor.

[@AutoRestoMod]

Did Vinnie put you up to this? LOL He actually has a multiple carb set up on a 350 in his Gen 3 Camaro. We'll look into it for sure.

[@11Xshadowolf]

I wish you would showed what you have the gauge hooked up to and what lines are dissconnected and what vaccume lines are connected can you just hook up the gauge to the brake booster port on carb and cap off advanced timing good info but still can't pay attention to it because not enough info on how to hook up the gauge and to what

[@wesleyhudnall3353]

I have no idea what to hook this shit up to. Been looking everywhere. Makes me feel stupid cause i guess its just assumed you should know where they go.

[@goldmamba2468]

Hook it up to the pcv vacuum going into carb

[@hughphillips67Mustang]

I have the same issue with my vacuum advance hitting the radiator hose. How did you reposition the distributor to avoid this?

[@MikeSmith-lu6ln]

These guys know their chit

[@maksimgeyman9290]

Can I disconnect the distributor advance hose that plugs into the carburetor and attach a vacuum gauge hose in that carburetor spot or should I place the vacuum gauge hose somewhere else in the carburetor or intake manifold. I have a 200 inline 6 engine 66' coupe

[@MrDLRu]

Hey guys, I have a 71' F100 w/302 and it idles in the 18-20 range. Though it flutters continually between that range and occasionally slightly smooths out, but not completely, for a few seconds and then back to the flutter...Any ideas what's causing this condition?

[@daftnord4957]

mustache guy looks like Freddie Mercury's brother

[@pedrosilvaslva2625]

he looks portuguese

[@maksimgeyman9290]

Do I use the same procedures if I have an incline 6 engine.

[@Maneatingturtle]

hey autorestomod, i have a 1965 ford mustang coupe 302 with a 1986 302, 3 speed trans that is automatic. the question is that the block has smog parts on it and has original 2 barrel intake and carb setup. can you pleas help? suggestions?

[@maksimgeyman9290]

What part of the carburator do you need to attach a hose or screw in. Mine is a 1 barrel carburator

[@irocn2010]

Do I need to buy a fuel regulator for this set up?? It has two pumps manual on the engine and electric in the tank

[@elementn4107]

I have a question i have a 1965 mustang 6 cylinders with an engine 200ci i got the engine rebuilt and everything but it souns like its going to turn off and the engine shakes alot what can be wrong with it

[@maddmaxx636]

Can you time a motor with a vacuum gauge? My motor seems happier at a higher base timing (The engine bay sticker say 10 degrees and I've got it running nicely at 13-14 BTDC) Could that be due to the age of my motor or the carb mounting gaskets are in need of replacing?

[@klarsen100]

Love the video but please show where you attach the vacuum hose! especially the vacuum advance section. I can't tell if you have the hose attached to the actual vacuum advance or not? Also, do you adjust the fuel/air idle screws first then the vacuum advance? Thanks!

[@AutoRestoMod]

Find manifold vacuum. We didn't show where we ported the gauge because Ford even moved the vacuum port. Most small block Fords have a vacuum tree on the back of the intake. To tune in the idle screws you'll need to go to manifold vacuum.

[@catgolfer1]

I have a Chevrolet 454 V8 on a P30 chassis. What is your opinion on these 'fuel injected' aftermarket systems for vehicles like mine. David 🐈

[@shanebowles2632]

Hay Jeff. I'm all the way in the UK and now we have an NPD warehouse here, do you know if they do many parts for the 68 Fairlane at all as this would be a huge help. Love the show fellas

[@AutoRestoMod]

Wow I didn't know that. NPD as of this time doesn't do parts for the Fairlane, You'd need to source your parts from places like Autokrafters or Dearborn Classics.

[@bigjon.6258]

Great Video .ole Man At the beginning reminds me of my Neighbor. Lol

[@AutoRestoMod]

That was my dad, he passed in 2016. He was a rip!

[@barryrichardson4314]

Hey I'm restoring a 1970 Ford Maverick would it be fair for me to assume that most parts used on the mustang can to used on the Maverick

[@markrutledge66]

I have a 67 Mustang 390 dual 4 barrels it runs off of the back carburetor it has a electric choke on the front carburetor shouldn't it have the electric choke on the back carburetor since that's the one that it's running off of until you kick it down and get the front four-barrel carb working?

[@Alicegt350]

Hey guys! One more helpfull video ! thanks! and if i understood well after the idle mixture screws have been set up i can rotate a bit the distributor to look for the maximum vacuum ?

[@mcbrideschmidte2803]

Yes. But there that can create a detonation issue so you will need to be careful doing that. If you get a hard-hot start condition you will need to back the distributor off just a bit.

[@AutoRestoMod]

Yes. But there that can create a detonation issue so you will need to be careful doing that. If you get a hard-hot start condition you will need to back the distributor off just a bit.

[@Alicegt350]

AutoRestoMod Ok i get it, slightly and slowly ! ^^

[@filmart430]

Do you connect the vacuum gauge to the carburetor or the intake manifold to perform the diagnostics you showed?

[@AutoRestoMod]

Intake manifold.

[@irocn2010]

Hi guys got a huge question!!! I got a 87 Trans am I been working on and can't seem to make it run right hope u guys can help!!! Ok I replaced the carburetor (e4me) q-jet electric one to a edelbrock 1406 because the old one was giving me nightmares! and I also changed the computer controlled distributor to a hei set up so I think I timed it right and all but now it runs rough and floods when I floor it. Now it eats gas like a fat lady at a buffet! Also electric pump still connected in the tank

[@davyhookbones]

Good video 👍 Just a quick question on a Olds 455 4v 380hp Rochester quadra jet engine what should the vacuum be at idle ?

[@AutoRestoMod]

Really depends on the overlap in the cam. I'd look for around 17-20 in stock configuration.

[@justinadams7890]

I know a sc tag when I see one 👍

[@wizardofx]

It's funny how so many of the younger guys haven't heard of the magic of vacuum in tuning. So if you run a big cam with a lot of overlap, your vac readings will go down. Then, at some point a vacuum advance doesn't help, especially if you need to raise your idle speed.

[@maksimgeyman9290]

How would I know if my carburetor needs to be rebuild

[@stephenfarrell1556]

I wish you would do an autolite 4100 air fuel mixture video

[@AutoRestoMod]

We have an Autolite 4100 on our '72 F100. It's kinda piggy right now so that might make a great video!

[@stephenfarrell1556]

I have a 66 Mustang with an Autolite 4100 that I just can't get right - not much on youtube where someone does a live setup of one of these.

[@AutoRestoMod]

I will say that the 4100 is VERY picky about airflow and vacuum leaks.

[@kevw0878]

Hello guys i have 95 FIREBIRD with a sbc (355) w/ th-350 im having problems carb or pump problem not sure!! Under a heavy load im hearing popping noise around 3000-3500 rpms running lean im guessing, to get to higher rpm i have to ease of the pedals but she stilll crawls up to higher rpms. (edelbrock 750 totally rebuilt and holley blue ) i need some help..

[@bernardhorig3785]

Hi Who you connect the vacuum gauge ? i have 1405 edelbrock 600cfm in manifold port or distributor port ,thx (sorry for my poor english i m French :-) )

[@AutoRestoMod]

Connect to the Intake vacuum port

[@yeudsiegal5285]

Adjust carburetor first, then Distributor?

[@luizfernandopaquieli3709]

Great vídeo! Let me ask you, is it possible install a carburator quite larger than required to the motor and adjust perfectly? I have a Ford V8 302 and I'm trying to adjust a Holley 4160 600 cfm on it, but till now I'm facing some issues to adjust it

[@I_like_turtles_67]

Did you get it figured out?

[@luizfernandopaquieli3709]

Hi Dan, not yet! Due to Covid here in Brazil I'm waiting some time to go back and try adjust again

[@krisztiàncsizmadia4206]

hi, could you help me how to connect the vacuum wire ford 460 lincoln in 1970-71?

[@AutoRestoMod]

It will need to go to a port on the carburetor. If it is a stock carb, it is usually on the base plate.

[@jamesgraham6796]

I wish you had shown Exactly where you connected the vacuum line. Thanks guys.

[@AutoRestoMod]

Find a vacuum port on the engine. On a Ford small block it is behind the carburetor.

[@mustardstain504d6]

Ford used multiple carburetion on many vehicles. I would like to see a segment that covers adjustment and tuning of them in detail.

[@AutoRestoMod]

We'd want to bring an expert in for that! While I feel comfortable mucking about with a single four barrel...multi carb set ups are outside of what I am use too.

[@troutteaser411]

I really liked your episode showing how to set your timing with a vacuum gauge. Everyone seems to generally agree that you should disconnect your vacuum advance when setting your initial timing. I can understand doing this when you're running off ported vacuum, but I don't understand why you would disconnect your vacuum advance to set your timing with a vacuum gauge if you are running manifold vacuum because the initial timing shouldn't be a factor since it will dramatically change as soon as you reconnect the vacuum advance. Am I missing something?

[@AutoRestoMod]

Thanks for the kind words Roy. It is done to set initial timing, to get a base timing signal.

[@MissShaftable]

I have holly 4bbl carb 600cfm on a 289 and have got it to 18 on the vac gauge (no air filter) I can turn the driver side idle mixture screw all the way out and nothing really happens, turning it in will bog the engine down, but the other one is more touchy, I can turn it in & out about 1 1/2 to 2 turns and I get rpm changes, also the rear float bowl always pours fuel out when I unscrew the sight hole, the front one is just rite. Am I in need of a good carb cleaning and should I mess with the timing and see if I get more vacuum? Any tips are appreciated. Thanks

[@alexandros8570]

Hello same, i turn idole mixture but nothing change I have only 10...

[@tonycolca2241]

This must have been filmed in oklahoma !

[@AutoRestoMod]

Close, it was Aiken, SC.

[@7008aspen]

So is it 20 or 22

[@jasondean3332]

I have a 1956 Oldsmobile with a 324. Where do I hook the hose to??? I don’t see any place to put it. I’m lost. Does anyone know out there ???

[@AutoRestoMod]

It looks like on the 324 the only viable port is the one on the carburetor that controls the distributor. You could tee into a test like to pull vacuum, but I'm not sure how accurate the reading would be from that port.

[@adammic16]

When u plugged the gauge hose into the carby,was the intake manifold hose left plugged or unplugged?

[@AutoRestoMod]

Always plug any open vacuum ports otherwise your readings will be off.

[@adammic16]

AutoRestoMod Ok..thanks for the quick reply too...love the channel.

[@AutoRestoMod]

No worries mate, We like us some Monaros!

[@1997LT1Camaro]

Whats the opinion on using a wideband in conjunction to tune?

[@AutoRestoMod]

Wide band sensor and guage can help with tuning for sure.

[@skylersmall6322]

My idle adjustment screw doesn't change the idle at all. It just stays at 1500rpm. unless I screw it in all the way then it goes up a little.

[@AutoRestoMod]

Check for binding on the throttle plates. Sometimes that can be an issue. It could also be a vacuum leak.

[@donrutter6765]

Skyler Small Start here. kzbin.info/www/bejne/gHWzqIxmgceFjLs

[@BeatersOrSleepers]

i have a 231-2v v6 buick engine and rochester dualjet 210 carb how and what vaccuum port can i hook this up and mount it so i always know how the engine is

[@AutoRestoMod]

You'll want to find a vacuum port on the intake for best results.