1996 - 2002 GM OBS Truck Vortec Engine CSFI / SCPI Fuel Meter Body Injector Rebuild (Vortec V6 & V8)

[@zackarymcclain164]

I have had 4 4.3 powered vehicles with the CSFI (spider injection) systems. they have all provided me excellent service. when the time comes that i experience problems with my vehicles i will convert them to the mpi style. theyre super cheap and they eliminate another point of failure.

[@jeffhatch9404]

I'm having trouble finding information for the MPI system for my 1995 Blazer W engine. Do you have any info you can share?

[@estevanorona9079]

Best video on this type of injectors. Very well explained and demonstrated. I will be tacking a 1996 Tahoe VORTEC in a couple days, very confident now! Thanks and stay safe!

[@mikewracher9511]

Nice to see a rebuild of this important system, also good to hear your thoughts on how well they work if maintained properly. I’ll maintain mine more appropriately and rebuild instead of replacing if it comes to that.

[@yogiberra47]

Thank You so much for your superb video. I can now rebuild my 2001 Silverado V6 injection spider.

[@KarenPlummer-xk7yr]

Thanks for the information. Done quickly without stupid jokes and no camera hamming!

[@ED-ti5tc]

Great video. About 7 years back I replaced my injectors with the upgrade. Can't complain. Thanks for video. Very interesting. Wish I'd rebuilt my old ones now.

[@HandySolution]

Awesome video!!! Thank you so much for taking the time to make these kinda videos!

[@servicioelectromecanicocue7025]

Cool. I can buy a kit with the Orings, micro filters, shrouds, and the nylon hoses, so i gonna reuse inyector and rebuilt the other parts. Thanks fotmr share, it's a super detail tutorial to do this job

[@herbertvortec4.3v64]

very good my friend, great explanation, your videos helped me a lot, in my country we don't have many videos explaining anything about vortec engines, thanks to your videos I managed to recover my blazer 4.3 v6 97. thank you very much!

[@NishnobsRUs]

Omg you the man thank you for taking time to make this video world needs more guys like you

[@WhatLarry]

Great video. I’ve been trying to find a complete ac delco spider fuel injector kit to have for that day In the future I need it. I’m sure you’re aware it’s impossible to find. Now that I know if I can properly diagnose which spider injector failed. I won’t need to replace the entire unit with an aftermarket one. I got a 98 gmc 1500 w/ a 5.0 and I’m cataloging these videos. Thank You

[@couchrider6228]

Great video. You are a good teacher.

[@MrRoy-rb1je]

Absolutely exceptional!!

[@blueduck8431]

Great video. I have a 1997 California Rig with a 5.7 the lines going to the poppets cracked and started leaking at 134,000 miles. I just replaced the whole unit with MFI. That was 4 years ago. The only issue I had was a failed pressure regulator only after a year. Things just aren't made like they used to be...

[@eladlutz]

Thank you sir. Have a 98 z-71 5.7 362,000 probably needs this done...lol

[@dinonaccarato2989]

Ohh excellent video too

[@jostinaviles-qi3jo]

Excelente esplicasion chilo carnal

[@richh9904]

My 1998 Silverado still doing fine with 114000 miles.

[@brandonkelling962]

WHAT A VIDEO FANTASTIC !!!

[@cartoonist1975]

i appreciate this video very much and still have my AC Rochester unit on my L35 vortec at 208 thousand miles in my obd2 '97 sierra 5speed. try and stay away from them made in china and made in mexico deLco's cause i seen that regulator you pointed out and how it was different from what came on your unit . you can still source new old stock for these . like my fuel pump i was able to find the square plug since i didnt want to solder in that oval plug when they decided to substitute the fuel pumps you had to change the wire harness out for the oval plug provided with the new pump. i like the deLco made in canada and detroit since they're spot on and plug n play but i also know there not easy to find.

[@braddock87]

Thank you for the video

[@joemontano71]

5:27 Chevron: Techron additive, engine treatment (CPS266362). 5:43 ACDelco: Excelda additive, engine treatment (88865595). 16:03 Fuel regulator assembly ACDelco (19210686) GM (19210686). 16:57 Spider body rebuild kit: ACDelco (217-451) or GM (17113205). 17:53 Injectors: ACDelco (217-265) or GM (17091432). 18:38 Reassembly.

[@boardsnmotion]

The problem is not bad gas it is bad engineering. Every other vehicle manufacturer from this era was able to produce fuel injection systems that did not require "Top Tier" gasoline. This spider injection system was used in pickups and suvs. Low horsepower simple vehicles that should have easily run on the cheapest gasoline available.

[@erikredIV]

400,000 miles seems reliable to me

[@molly18239]

I owned a 97 and an 02 K1500 and I replaced those spider assembles with the updated "new design" ones (MFI). Both trucks ran much better. And currently I have an old 95 k1500 with TBI, so I don't have to worry about those "spider" assemblies any more. A TBI rebuild takes like 20 minutes once it's off the truck.

[@RonButler-u6u]

Is it cheaper to just order a hole new assembly ,and are they attainable ,You make that look easy.......

[@DrShock]

You cannot order a complete CSFI anymore, they've been discontinued by GM for many years now. Only an MFI is available, which came out for later year trucks after the GMT400 series went end of life and would not be original equipment.

[@JamesSmith-xs7sr]

I just replaced the injector assy on a 97 5.7 sierra. Misfire # 5 cylinder (constant misfire) Owner replaced assy 2 years prior with an Amazon ordered unit. Said it ran good for over a year. I took the top off, # 5 & 7 injectors were reversed! Fixed it, runs proper. How could it have ran properly at all, after 5 & 7 installed in the wrong intake port???

[@dinonaccarato2989]

Zacherymcclain, I have purchased two different mpi fi, one from Amazon /china and the second made in the USA. Both have leaked and I’m still having issues. I would suggest to rebuild or purchase OEM for this part. Wouldn’t want anyone to go through this like I have been. Just my two cents. Dino

[@johnmckenna8989]

Great video...We have to change out a set on a 2001 Jimmy 4.3....What is the cost saving between just buying a new set or rebuilding like you've done ? ....... We've always used an additive/cleaner in our fuel (STP type) but can't speak for the previous owner...I'm 76 and always had carburetors, so it's all new to me (Been driving my car for 53 years now) ....Thanks for posting this video....

[@DrShock]

Thanks. On these original CSFI/SCPI systems you can either rebuild them yourself, as I've shown here. Or you could convert it to the newer MFI system that was introduced in later generation engines as well. I don't believe anyone is selling CSFI/SCPI type systems new anymore. The MFI setup will typically be available complete as a plug and play drop in, whereas the CSFI systems being much older will only have a rebuild it path to go with. Personally, I prefer to keep things all factory as-built original even in an old GM truck, so the rebuild path is what I've shown in the tutorial here.

[@justatool]

Very detailed explanation, what made you decide to rebuild this? Did the engine have a loss of power? Did this fix or improve the issues you were experiencing? Is there a follow up video? I have 3 vehicles with this engine 1 has very good performance and the others have always been sluggish. I'm hoping this will help me with mine. I like these older body styles and hoping to hold onto them and get more miles out of them.

[@DrShock]

We had to rebuild the intake manifold on this particular vehicle due to oil leaks from aged gaskets. Since the vehicle was approaching 400K miles, it was a good time to refresh this assembly as preventative maintenance for the next 400K. It was one of those _while we're in here_ sort of decisions.

[@PaulBassen-p8o]

Hello again, I got my injector assembly mostly taken apart at the moment. Injectors are activating when supplied power so I tied bread tie metel and tried to tug out the poppet to flush lines and all but kept breaking the wire so I used vise grips and pulled really hard a few times with no movement. So have them all pulled out and soaking in hd degreaser overnight will try to move them again In morning.

[@DrShock]

They can be really wedged in there, so you may have to tap them out as I showed. I don't know that you can remove them without causing damage, they were only intended to be removed in order to replace them.

[@brunopecego5297]

Ive seen some people say that you can adjust the flow on these injectors by turning a tork screw that’s underneath the resin drop between the two eletric conections. My truck is running rich and im thinking about doind that. Apparently some models even have a cut in the plastic housing to access that screw but mine doesn’t and I’m reluctant to cut a hole on that plastic

[@RichardHarris-qh2gy]

make sure your temp sensor is ok, my 96 was running rich and the dash temp read good,but the scantool engine temp was off.replaced temp sensor (cheap fix ) good to go.

[@joshclark4513]

Perfect car repair video! I may have skipped past some of the book talk at the beginning where you said it but, why did you not just order the whole assembly new online? I cannot even find the rebuild kits unless i look up your part numbers from your video

[@DrShock]

Thanks, you never could buy a CSFI as a complete assembly, only as the individual ACDelco parts I showed here. You're thinking of the later design trucks and the MFI design with the electronics on the ends instead of in the body. I mentioned this in the beginning.

[@jeffhatch9404]

I'm having trouble with my 1995 Blazer W engine. I need to find a rebuild kit for the spider.. I have 4 junkyard spiders that are all bad. This has been going on for months. Please help if you can.

[@dioscurimas1018]

Fantastic video, Its amazing how complicated these components seem until its broken down like this. I have a 1994 S10 in which I would like to rebuild the spider. My spider is different than the one you rebuilt. Can you tell me what resource you used to find the rebuild kit, Fuel injector, fuel regulator etc. part #s. Thanks in advance

[@DrShock]

Thanks, to identify the part numbers I have access to the genuine GM parts department online parts finder and parts diagrams. But you can find very similar parts breakdowns at many online GM dealership parts department websites online. Once you have the part numbers it will _always_ be cheaper to purchase them on eBay, or Amazon, rather than the dealership.

[@dioscurimas1018]

@@DrShockThank you for the quick response. My truck is waiting in the driveway and my son is ready to be back in it. Thanks again.👍🏻

[@dioscurimas1018]

@@DrShock Hello, I took your advice and had some success. I was able to find a pressure regulator for my fuel inj. spider. However, my issue revolves around the change over GM made in the fuel inj. spider design in my 1994 S10. I have the first interation of the spider. It has on central injector and 6 fuel lines with three lines on each end of the siper. My Spider Part # embossed on the unit from my truck 17084904. I am trying to find the single injector however every search I make turns up the newer version of the inj. The injector I'm trying to replace has no part # on it just a 4 digit # 8225. I would like to do a 100% rebuild including the 6 fuel lines, nozzles, clips, o-rings etc. If you could share any further knowledge you have on this topic I would greatly appreciate it. Also it's becoming hard to find these spiders at all unless one is willing to pay $450 used or $650 rebuilt. Most auto parts suppliers are out of stock. A rebuild video on this specific spider would probably gain some views. Again, Thanks in advance.

[@DrShock]

Is this a 1994 4.3L V6 engine? If so isn't ACDelco 217-1431 / GM 17113673 your complete assembly?

[@dioscurimas1018]

@@DrShock Yes that is the assembly I have. Those are two of the many different part #s that lead to this spider. The # embossed on my spider block is 17084904. Most auto parts suppliers do not have this unit in stock. The few Ive found are very expensive. I was hoping to rebuild the one I have. Locating the appropriate injector for this unit is the problem I am having. Every search I've tried using these part #s lead me to an inj. that is for the redesigned spider. So that is where I am. I can't seem to locate any of the individual components from this spider other than the pressure regulator.

[@YoungHeartedSoul]

wow amazing video!!! did not know this F.I system could be rebuilt .my poppet valve injectors are long gone. would you know where I can find the O-rings and washer retainers? I did a MPFI and lost the O-rings and washers. I wonder if there is a kit available.?

[@DrShock]

Thanx, the GM CSFI / SCPI kit I used is listed in the video description, along with purchase links.

[@YoungHeartedSoul]

@@DrShock thank you sir.

[@camaromustangmods3327]

Why don't you recommend the replacement vs the stock poppets? I used the replacement GM units years ago. I know the new units out there are not GM. Thanks for the video. Didn't even know these could be rebuilt.

[@DrShock]

I mention in the video, and in the description, that you could go with the later design MFI update instead of rebuilding the original design CSFI style. There are plenty of other videos about that sort of modification so not that interesting to record yet again. So I've spent my time on the more unique video, about doing what would have been done in any GM dealership of the 1990s before MFI ever existed, which is rebuilding the original CSFI design injection. Keeping it all genuine GM, all original, and restoring it back to its original factory specifications and condition.

[@camaromustangmods3327]

@@DrShock Thanks for the reply. My late dad worked at a GM dealership from 79-96. Good memories from that growing up. Thanks for all the great videos.

[@boatmoter7464]

Question. what is the Plunger with the long tube that is behind the screen filter & regulator assembly, I see you did not take it out. what is it's function? I am having trouble with mine, it bypasses the unit back into the tank leaving 0 pressure for the unit . I already installed a new regulator on it. same thing? held unit with hand plugged into the fuel lines, it just bypasses?

[@DrShock]

Anything I didn't remove is not serviceable separately. I believe you are talking about part of the black plastic fuel meter body assembly that sits behind the regulator. If so, then you would replace the fuel meter body assembly itself to address a _confirmed_ issue there. There's a link in the description for both the V6 and V8 flavors of this part.

[@chrisfoley3320]

Why was one of the injectors a different color. Great videos man

[@DrShock]

Thanks. The technical documentation is pretty sparse, but I would say the difference in colors is simply different OEM suppliers to GM/ACDelco having different color plastics.

[@RodneyWesling]

Are the 2 silver prongs on on the injectors just guide pins?

[@DrShock]

I believe you are referring to the electrical connections for the injector.

[@speedbuggy7240]

Would this work on 93 4.3 vortec? I'm having a vey hard time finding new or rebuilt spider injector my 93 S10 blazer 4.3 vortec.

[@DrShock]

Should be very similar as the V6 used the same type of system.

[@lonmiller5265]

I'm curious as to why you don't like the replacement spider injection system that has the wires running to the nozzles. Is there a problem with their reliability? If so please let me know, thank you.

[@DrShock]

There's nothing wrong with MFI, it is in fact newer technology and a GM supported backservice option for originally CSFI vehicles that encountered problematic carbon buildup. But MFI just isn't how the vehicles were originally manufactured, so not something that interests me personally. I've spent several decades doing factory show car restorations on GM engines of the 1950s and 1960s. Putting them back to the exact original assembly line condition right down to the head bolt and inspection paint marks. Chasing down that exactingly correct shade of paint on a wiring harness bracket. So I tend to treat even routine repairs and maintenance, on even an old 90s truck like this one, nowadays with the same attention to detail and GM originality is all.

[@ericpimentel2453]

The terminals can be installed 180 degrees, or 360. Do the injectors have a positive and negative terminal, or can they be installed either way? How can i tell ?

[@DrShock]

If you are referring to the step starting at 28:03 then the new GM injectors will be pre-bent out of the box. I always align them where that bend will put the line facing outward as you see in the video. I'm not aware of any polarity concerns with this step, nor does the GM service manual mention anything about them having polarity. I follow this procedure more so from bing focused on not stressing the lines given these are available as NOS type parts only nowadays.

[@brandonkelling962]

Hey quick question if you don’t mind. I just bought a 1999 GMC Sierra 4.3 v6. The engine starts beautiful when it’s cold but when it’s warm it takes 3-5 seconds to turn over. Do you think I need to rebuild the spider or what steps would you take. Also I think it has the CSFI like you showed ? Anyways thanks for any tips.

[@brandonkelling962]

Fuel pump was replaced last year guy said and I replaced the fuel filter yesterday (full of rust)

[@brandonkelling962]

@drshock also my fuel lines are hard so can’t pinch them off to troubleshoot

[@DrShock]

These kind of problems are not ones you can work over a comment board. You'll need a GM service manual and some special purpose tools, e.g. J-2534 class scan tool and fuel pressure gauge, to progress this yourself. The fuel pressure gauge can confirm that the fuel pump module is delivering, hot or cold, the correct psi. The scan tool can monitor crank rpm signals hot or cold, any misfire counts, any VCM DTCs, fuel info, etc. The data obtained can guide further diagnosis using the service manual test trees. These kind of symptoms you describe could be fuel system or ignition system, typically. Multiple reasons, multiple causes, and of course multiple repair actions for each. It's just not something that can be determined without hands-on examination of the vehicle. But I'd start with the fuel system if it were me. Given the corrosion captured in the previous filter, I'd also include inspecting the fuel hard lines that feed into the filter, as well as the tank itself. None of that is part of the hot starting symptoms, but it could be something that needs more urgent attention before a fuel line or tank starts leaking due to rust through.

[@julioolbera7431]

I have a question would you know if your injector is still good if you damaged the middle wax between the two prongs?

[@DrShock]

If it's just the epoxy seal that was damaged, you can reseal it to insure no fuel gets into the electronics. It should have no impact on the operation as long as you didn't run it like that.

[@v34jj]

There is a screw in the star shaped fuel injector assembly can you help me because I have it unlocked

[@DrShock]

Are you referring to the adjustment screw that is embedded in epoxy at the end of the injector? If so, you'll have to replace the injector. There is no service information available from GM on adjusting that as it's set at the time the injector was manufactured.

[@chub_boi7391]

I can’t seem to get the spider to seal into the upper intake. I thought it would pop into place when torquing down the intake but still nothin. Any tips on how to get it to seat? I ended up breaking the screw that holds the fuel line on while trying to pry it into place

[@DrShock]

The reinstallation procedure into the intake manifold isn't covered in this video. But I believe I mentioned in my upper intake rebuild video series you definitely do not want to try to draw the spider assembly in just by tightening the upper intake fasteners. The GM service manual page mentions a similar caution. It's decades old plastic now, and was very likely to crack even when it was newer. During the rebuild that oval seal at the spider assembly needs to be replaced, and lubricated. The mating surface for this seal in the top of the upper intake plastic cleaned and also lubricated. And the spider assembly has to be fully snapped into and seated on the metal bracket that is part of the lower intake aluminum casting. The metal bracket intentionally has some play built into it where it attaches to the lower intake aluminum manifold to aid in reassembly. You mate the two together just with downward pressure by hand on the upper intake manifold. You'll be pushing down evenly this way, using no tools, which will avoid damage to the plastic parts involved. It will take some time as the friction fit is difficult. But it will slowly go. If not, stop and look for obstructions or related component alignment issues with the spider assembly seal.

[@plague-wv4rm]

Could i do the same to an mfi set? I cant seem to find the oem assembly i figured i can just rebuild with the injectors from another mfi assembly.

[@DrShock]

The MFI design was not intended by GM to be rebuilt, so the individual parts are not available separately to do so like with the CSFI. You may be able to scavenge from other units, but idk for sure.

[@andyvaldez2830]

Is there a way to diagnose the fuel pressure regulator without removing the upper intake manifold?

[@DrShock]

The regulators _rarely_ go bad on these OBS trucks, if its a genuine GM ACDelco regulator. The only evidence _might_ be leaking fuel externally from the regulator housing since there is no external vacuum line with this design. To determine whether it is leaking, a small camera thru the throttle body, obviously with the engine off, _may_ reveal evidence of that without disassembly.

[@andyvaldez2830]

@@DrShock Thank you sir. I hadn't thought about the camera idea. I will definitely do that. Here's our dilemma. Our 1998 5.7 vortec will crank but not start unless you apply the throttle. As long as you apply the throttle it will start and run smoothly. As soon as you release the throttle the RPMs drop to below 500 and the engine struggles like it is starved for fuel and it eventually dies. The fuel pump module sounds horrible so I was thinking that it was the culprit. Fuel PSI with the key on and engine off is 60. Fuel PSI at idle and at full throttle doesn't go above 53. Someone had mentioned to me that it could also be the fuel pump regulator and I was hoping to be able to diagnose that without removing the upper intake manifold.

[@DrShock]

Those symptoms could be a number of things. Fuel, air, temperature, or ignition. But you should eliminate fuel first. It's not one for the parts cannon, or will get expensive really quick. Needs a proper diagnosis with a scan tool to zero in. But since you seem to have a fuel pressure gauge, measure that on a cold engine. Key on, key off, 2X. GM factory spec in this engine off state is 60-66 psi with the fuel pump running (audible noise). With the engine started and then idling it should be no less than 55 psi. You said you measured 53, that's _slightly_ below specification and could be a clue. If the fuel regulator were leaking, then fuel pressure would not hold at a steady psi and drop (this can also be caused by a leaking injector(s) - either way you have to open up the upper intake). This, plus the camera inspection, are the two checks for leakage I could suggest without access to a scan tool. Low fuel pressure, but still steady, points more to the fuel pump, or a fuel line/filter obstruction (presuming the fuel lines themselves are not leaking due to corrosion/damage).

[@andyvaldez2830]

​@@DrShockThanks again for taking the time to reply on these old videos. What the issue ended up being was a dirty idle air control valve. I removed it from the throttle body and there was a lot of carbon buildup around the tip. I cleaned it up and reinstalled it and the engine starts and idles much smoother like it did before. I feel like I should go ahead and replace the part anyway since it is 25 years old. Initially I was thinking fuel pump but glad I kept doing research and received some input from good friends. 👍

[@ScottFree-dl1vy]

More commonly known as spider injection.

[@bobbygzzz7116]

Do u sell these...systems all rebuilt???

[@DrShock]

No, I don't.

[@BoB-nk7wx]

The unit in my truck is filling up with gas, why is that?

[@DrShock]

If you are referring to the fuel meter body, this would be an injector, or its barrel seals, having failed imo. If you are referring to the intake manifold, then I would be more inclined to look at the fuel regulator housing.

[@mtebaldi1]

Nickname Spider injectors.

[@michaelmiller5618]

Yes you can rebuild this spider injection system but why would you? I believe you would be better off replacing the entire unit. On a van especially it is a pain in the as* to replace these do you really want to put it all together just to replace broken lines in a month or so. I want reliability even it costs a little more.

[@CollinsDouglas-q9y]

From Ebonyi State Nigeria please I need the Nuzzle new one. How much?

[@JCnordic2983]

Id love to adapt this to y dodge 3.0

[@jasongoulart-jf6zg]

WD-40 works great

[@brianneston8575]

The newest system would have problems too. But they should have done as they should have went with the marina fuel injection. Are the same fuel injection they had in the cyclone in that typhoon! The ones that are hated on Chevy the Ford owners Ford have the camshaft synchro wasn't that good either

[@charlesrobinson8143]

Gm just dropped the ball with this spider injection foolishness

[@josecfish5297]

I’m in CA and My 1994 s10 blazer has this setup vin8th letter W and I don’t like this setup it’s completely garbage rusted fuel tank carbon build up&cheap gasoline = expensive spider injector prone to failure GM”s worst fuel system design ever there should be a recall on all these CPI nonsense I feel like seriously sending this truck back to them (lawsuit) or to junkyard because of this setup.

[@WTFIsThisGuyDoing233]

Awesome video. Just do the upgrade though.