Fuel Injector/spider How To

[JoshBarber]

yes sir

Originally Posted by 98 headache 4.3

great write up. done like a pro. I wanted to know if after making the swap to MFI does it always start first crank?

[PawNtheSandman]

Could we get a reup of that pdf file?

[ginobass]

The link to the MFI conversion PDF no longer works, is there another source?

I looked at those part numbers on GM Parts Dirct, the descriptions are poor, part 12568332 ($154) just says 'injector' - is that the entire assembly, or just one? Didn't say anything about a regulator included. Bracket was 20 bucks and gasket/seal kit 23.

[TomB985]

I have a '95 Blazer, and I'm curious about how the fuel fittings on the back of the plenum are sealed.

I replaced the CPI/nut kit back in March, with no leaks and everything working. I never used anything to seal the fuel fittings, and it worked just fine. Now I just tore it all down again to replace my intake gasket, and when I got it all back together, I have a continuous leak out of the fitting on the fuel sending line...the return line seems fine. I tried thread sealer on the threads...is there another way to seal them? Or is it just a pressure fitting, and I should just tighten it up?

Thanks!

[FisherJD]

Does anyone know if this will work on a 1995 4.3L "W" and if this is all the parts that I need to update the spider:

12568332 - MFI Assembly
88894355 - Bracket
17113215 - Seal kit

I can't find the link for the GM Service Bulletin either.

Thank you!!

[TomB985]

Not quite, you have the numbers for the '96 and up 4.3s. I just got done with this job last night, here's what you need:

CPI: 217-1431
Intake manifold gasket

It's also recommend when you have it apart to replace the lines running into the injector, also known as a "nut kit" which is part "17112705"

I ended up doing this job twice, once six months ago, and once last night due to the CPI failing again and causing the same problem. First time it took me about 3 1/2 hours, last night it took me just over an hour and a half...once you do it once it goes much faster. Good luck!

[FisherJD]

I am confused.

Does that mean that I can't convert my 1995 4.3L v6 "W" from Central Port Injection (CPI, Part numbers ACDELCO# 217-1431 or GM# 17113673) to Multi Port Injection (MFI, GM part # 12568332)?

GM Service Bulletin # 00-06-04-003B indicates that the conversion can be done on 1995-2002 Chevrolet S/T Models. GM lists these parts:

12568332 - MFI Assembly
88894355 - Bracket
17113215 - Seal kit (Intake Manifold Gasket) * Is this the correct one for the 1995 "W" engine?

They don't mention the "Nut Kit" (GM part # 17112705) but I am sure as long as I am already in there it would be a good idea.

I would really appreciate any assistance as I am a Newbee

[TomB985]

I did some research, and I have found a reference to a conversion, but I haven't found much on it. I think it would be very difficult to do, however. Consider, your PCM is set up to fire one injector...the MFI system uses six. How would you control it? obviously it's a different wiring harness, and that would also require a new PCM and a new main harness...you're talking probably over $1,000 in parts...IF you could get it to work. There's no real benefit to the other system other than the fact that it will not fail every 100,000 miles...

I'd just replace the CPI with the same OEM unit, and live with it. Most of these trucks don't see 200,000 miles, so i doubt you'd be replacing it again.

[anthonyalan]

I am in the same boat as Fisher. My Jimmy hasn't ran for almost a year, and a mechanic told us it was the nut kit, and instead of telling us he would fix it, offered to buy it from us, since it isn't worth that much. I figured me and a buddy could change it with the proper instructions(I was hoping from AF). I also have the "W" VIN which seems to be different from this write up. Is there any other write that show how to change the nut kit on the "W" VIN? Or is this one similar enough to use on my Jimmy?

[TomB985]

What year is your jimmy?

[anthonyalan]

It's a 92

[FisherJD]

Anyone still looking for the Service Bulletin # 00-06-04-003B, I did find it at:

http://members.shaw.ca/betterthanyou...g%20Poppet.htm

This works great on 1995-2002 Chevrolet or GMC S/T Models, with 4.3L, 5.0L or 5.7L Engines(VINs W, X, M, R). This modification was developed by GM for use on GM vehicles. It does not require any rewiring, only the new MFI Injector (part # 12568332), Manfold seal kit (part # 1711-3215), and a new bracket for the MFI Injector (Part # 88894355). NOTE These parts are for a 4.3L V6 (Parts for a V8 are listed in the service Bulletin).

My S-10 has 142,000 miles on it and now runs like it did when it was new!!

[hernandez3674]

THanks Josh for your write up.. based on your post i purchased the same parts thru gmopartsdirect and in less then two hours i was on the road again. Tremendous difference for me since i notice mine CPI was leaking ... well worth it. thanks

[terryl50]

Hey, I'm new to this site but this is a great post. I'm about to do this upgrade kit to my 2000 4.3 Chevy Blazer. One slight problem I've run acrossed. How do you get to the fuel supply lines near the fire wall to disconnect them. I'm guessing there's a wrench for this I just want to know the proper approach.
Thanks to everyone in advance.
Terry L

[johnhutchinsusa]

Terry,
On my 2000 Jimmy, I use a 16mm crowsfoot (Craftsman) on the end of a long 3/8" extension. Once it's broken loose, I can unscrew the rest of the way by hand.
If there was space, the proper wrench would be a flare nut wrench.
Good luck,
John