This is being done on my 98 Blazer LT 4x4

After realizing that the dealer wanted to charge me 3-4 hours labor ($89/hr) JUST to remove the upper intake.....not including any work within, I decided it was a definite DIYS!
After removing it once....it takes no more than 15-20minutes at most.

The most important thing to remember is you need to immediately block your intake ports firmly with shop rags. If not, you may learn the hard way...as I did....that you can easily lose a part or tool inside and find yourself removing the lower intake as well....with much aggrevation, and time wasted.
I can't say it enough! It takes 5 seconds to be safe.

As soon as you remove the upper intake cover:
BLOCK YOUR INTAKE PORTS IMMEDIATELY BEFORE ANYTHING ELSE!

Disconnect your battery, and relieve the fuel pressure from the system at the fuel rail (either with a vent on a fuel pressure gauge, or pressing in the valve pin holding a shop rag over it to catch any excess)

http://i16.photobucket.com/albums/b40/JoshB_/fuelspider/1.jpg
Remove your air intake as a whole. (4 screws on filter, and twist screw on top of throttle body)

http://i16.photobucket.com/albums/b40/JoshB_/fuelspider/2.jpg
Disconnect the fuel supply and return lines at the firewall (16mm)

http://i16.photobucket.com/albums/b40/JoshB_/fuelspider/3.jpg
Remove the 12mm bolt securing the lines to the bracket.

http://i16.photobucket.com/albums/b40/JoshB_/fuelspider/4.jpg
Remove the two 8mm nuts securing the fuel lines to the fuel meter body. (This is what I dropped into the intake, and they're NOT magnetic!)

http://i16.photobucket.com/albums/b40/JoshB_/fuelspider/5.jpg
Remove the four 10mm bolts securing the throttle cable brackets.
http://i16.photobucket.com/albums/b40/JoshB_/fuelspider/6.jpg
http://i16.photobucket.com/albums/b40/JoshB_/fuelspider/7.jpg

http://i16.photobucket.com/albums/b40/JoshB_/fuelspider/8.jpg
Remove the throttle cable and cruise control cable. The cruise cable will pop off backwards, but you'll need to relieve the tension and take the throttle cable bullet off to disconnect it.

http://i16.photobucket.com/albums/b40/JoshB_/fuelspider/9.jpg
http://i16.photobucket.com/albums/b40/JoshB_/fuelspider/10.jpg
Disconnect all electrical connections (including the main fuel spider connection), and using a DEEPWELL 10mm socket, remove all 10 bolts securing the upper intake cover. Gently guide the fuel meter body back out of the cover, and remove the cover.

http://i16.photobucket.com/albums/b40/JoshB_/fuelspider/11.jpg
You now have access to the fuel spider. Using a flat screwdriver, gently pry the tabs of the fuel meter from the bracket securing it. Pinch the injector tabs and remove the poppets from their holes.

http://i16.photobucket.com/albums/b40/JoshB_/fuelspider/12.jpg
Inspect the fuel spider thoroughly for leaks. If it appears as though the injectors are leaking from underneath the fuel meter body, you can remove them individually.

http://i16.photobucket.com/albums/b40/JoshB_/fuelspider/14.jpg
Remove the two 8mm bolts securing the metal bracket underneath the fuel meter body and set aside.
Using a small screwdriver and needle nose pliers, gently pry the plastic cap from the fuel meter body that secures the injector. Again VERY GENTLY, taking care not to damage the plastic injector line, pull the injector from the body using the the needlenose pliers. You may need to use a small dull screwdriver from the inside to help push the injector out.

http://i16.photobucket.com/albums/b40/JoshB_/fuelspider/15.jpg
With the injector free, you can inspect the two orings on each.

http://i16.photobucket.com/albums/b40/JoshB_/fuelspider/16.jpg
Here you see the Oring kit for the fuel spider which includes all o-rings on the spider, as well as the metal bracket and nuts that brace the injectors into the body. This seal kit is: GM # 17113205
Remove the Plastic retaining caps, and Orings. Be sure to use a slight coat of Oring grease when reinstalling them. Replace all Orings on the fuel meter body in the same manner. Now would be the time to replace the regulator if necessary. It's approx. $90 from GM.

http://i16.photobucket.com/albums/b40/JoshB_/fuelspider/17.jpg
Before reinstalling the spider, carefully inspect the two Orings on the fuel supply and return lines...replace if needed. You may also choose to replace the upper intake cover gasket at this time. It comes in a set with the Upper Intake Gasket, Throttle Body Gasket, and Fuel Meter Body Oring (seen in orange). This Gasket kit runs around $30, and is GM#17113215.

Installation is reverse of removal.

If you choose to replace the whole assembly, there is an updated fuel spider. Below are the part numbers and PDF GM Bulletin for the changeover. It's supposed to correct the problem of sticking injectors, and is half the price if you believe you may have more than one bad injector. It also includes the regulator, which alone is $90. NOTE: The blocked intake ports, and cleaned intake!

If you choose this route, as I eventually did, you'll need:

Here's the part numbers:
12568332 - MFI Assembly
88894355 - Bracket
17113215 - Seal kit

Here his the GM Bulletin for install (thanks to Blazee!):
http://www.savefile.com/files.php?fid=1709708

http://i16.photobucket.com/albums/b40/JoshB_/fuelspider/18.jpg

nice write-up

Good Job. Added to the FAQ.

Damn! That's a sweet write-up! Thanks!

Good job. Happy to see things turned out the way you wanted.

Good Job. Added to the FAQ.


FUEL MILEAGE APPEARS TO HAVE DOUBLED SINCE THE REPLACEMENT OF THE SPIDER!!!!!!! Will reply with actual mileage change

Excellent post!!! You are right, a picture is worth a 1,000 words... Looks like they have done away with the poppets... If your mileage has improved that will definately offset the cost. Is this this updated assembly very expensive?

Excellent post!!! You are right, a picture is worth a 1,000 words... Looks like they have done away with the poppets... If your mileage has improved that will definately offset the cost. Is this this updated assembly very expensive?

$300 - $400 from the GM dealer.

Less than $200 from www.GMPartsDirect.com

Thanks Blazee, I will look into replacing mine, sounds like gmpartsdirect.com is the way to go...

Did installation of the MFI assembly require any special instructions?

Did installation of the MFI assembly require any special instructions?


It's pretty straight forward. That GM Bulletin that (Blazee) and I provided the link for, gives the specific directions on the install. It's pretty much just replacing the bracket (it sits in a specific direction front to back), and making sure the fuel injector lines are in a specific routing. I believe one has to run under another etc. And then its just making sure the electrical connectors at the tip of each injector are facing the center of the intake to allow clearance when reinstalling the cover. It also notes that once the injector has snapped into its hole, it should not be removed or it may damage the tip.

Great write up

Thanks guys! This website rocks big time!!!! Replaced the spider assembly this evening and I am still in shock at how responsive and quick my '98 suv is now running! Hope my gas mileage will improve as well... Checking for lower manifold leaks and so far so good as well (after replacing the gaskets the 2nd time and torquing to correct specs). Saved serious $,$$$ over the dealer as I replace both oil cooler lines, spark plugs & wires, rotor & cap, lower & upper manifold gaskets and replaced the fuel injector spider assembly. I seriously could not have done most of these jobs without your help!

Thanks again.

Thanks guys! This website rocks big time!!!! Replaced the spider assembly this evening and I am still in shock at how responsive and quick my '98 suv is now running! Hope my gas mileage will improve as well... Checking for lower manifold leaks and so far so good as well (after replacing the gaskets the 2nd time and torquing to correct specs). Saved serious $,$$$ over the dealer as I replace both oil cooler lines, spark plugs & wires, rotor & cap, lower & upper manifold gaskets and replaced the fuel injector spider assembly. I seriously could not have done most of these jobs without your help!

Thanks again.

Glad to help bro. Judging by the fact that yours is a lot more "responsive and quick" now, (if the spider made a difference I'd say the injectors may have been stuck partially closed...where mine were stuck open. That was the problem with the old spider assemblys. Don't ask me why GM never recalled them when so many different models used them....also,
I'd say the new plugs, wires, cap & rotor are likely causes of the quickness as well.

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

yes sir

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

Could we get a reup of that pdf file?

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.

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!

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!!

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 (javascript:displayDetails( 'ACDELCO', '21', '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!

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 :banghead:

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.

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?

What year is your jimmy?

It's a 92

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

http://members.shaw.ca/betterthanyoutoo/Sticking%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!!:)

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

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

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

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


Hey, John thanks for the reply. I already have it off, but your post will help with the install, If you have done this before I do have one concern before I order the update from GM Parts direct, Is this 100% the correct part # 12568332 I tried emailing them but I haven't got a responce yet, also how long does it take for them to ship it to you.

Hey, John thanks for the reply....

I still have the old style injection body, but having tried to get it to stop leaking for the last 2 weeks, I see the MFI upgrade coming.
So far as the nuts on the fuel lines, be sure and check or replace the o-rings when you reassemble.
Good Luck
John

Hey, John thanks for the reply....

I still have the old style injection body, but having tried to get it to stop leaking for the last 2 weeks, I see the MFI upgrade coming.
So far as the nuts on the fuel lines, be sure and check or replace the o-rings when you reassemble.
Good Luck
John

Hi again thanks for the advice already have them. The only thing that I'm waiting for is some type of verifcation that this is the right part. So I can order the upgrade. My manual says that I have a CSEFI fuel inj , GM Direct and the post from GM on the install says that this is for a SCPI to MFI UPGRADE, My question is, are CSEFI and SCPI one in the same? They look the same according to the pictures. I just don't want to order the wrong part.
Thanks Terry

Terry
Got reply today from GMDirect. You probably heard from them by now.
I picked my parts up from a dealer friend on Wednesday.
Looks like it should fit perfectly, but weather hasn't allowed me to get it on yet. I/m excited about getting that old dog of an injector body out and putting the better design in.
Let us know how you come out.

(from GMDirect)
"pk12568332" is the correct part number for your vehicle, per the VIN
supplied.


Thank you for choosing www.GmPartsDirect.com


Subject: Part number verification

**Please confirm part numbers and pricing for:

2000 GMC Jimmy 4.3 L Vin 1GKDT13W8Y2103XXX

1 each pk12568332 MFI upgrade

1 each 88894355 V6 Bracket

1 each 17113215 V6 seal kit

Got the 2000 Jimmy put back together today.
MFI part numbers in above message fit/work no problem.
Have other issues, but by george, my leaking fuel pressure problems are gone!

John

OK, I need some clarification.

When I went to change my CFi injectors origianlly, I apparently got the MFI injector. It did not look like those injectors would fit into my lower intake manifold. So does the lower intake need to be replaced as well? From the parts list you have up there, it seems not. Also the computer works the same? I do not need to replace any other of those electrical sensors? If not, that is great, but I am just curious.

It definately seems the CFI has all kinds of problems and the MFI is the way to go. I replaced the CFI injectors and apparently now I have a huge vacuum leak somewhere so I need to take it all apart again to redo it to triple check what is incorrect. Since I am doing it again, I am thinking maybe do this conversion and end the issues with this fuel system.

FYI, 96 GMC 5.7.

Any input you all can have for me I would appreciate it.

Thanks.

On 2000 GMC Jimmy 4.3 6cyl W engine, the only thing I had to watch out for when putting the MFI spider in, was turning the injector connectors so that the upper intake cover would fit. Everything else seemed to go slick.

Good luck
John

Hi John, I just got my order in from GM parts Direct. I have run across what I hope is not a problem. All my fuel lines coming off the the fuel meter body are facing towards the fuel pressure regulator. according to the install they all need to be away from the fuel pressure regulator was yours like this or did I get a bad one? It's doesn't look like the fuel lines will turn 180 degrees. I don't want to damage it, Just wanted to know what yours looked like when you took it out of the box.
Thanks

Hi John, I just got my order in from GM parts Direct. I have run across what I hope is not a problem. All my fuel lines coming off the the fuel meter body are facing towards the fuel pressure regulator. according to the install they all need to be away from the fuel pressure regulator was yours like this or did I get a bad one? It's doesn't look like the fuel lines will turn 180 degrees. I don't want to damage it, Just wanted to know what yours looked like when you took it out of the box.
Thanks

Like yours, mine had the lines turned around to fit the plastic formed packing.
I gently turned them around to the front without problem.That tubing is probably pretty tough, but I treated it gently anyway.
Number 3 has to slip behind number 1 slightly. Position connectors like the technote describes towards manifold so upper half goes on OK,
Details:
http://members.shaw.ca/betterthanyoutoo/Sticking%20Poppet.htm
Between the excellent AF How To and the tech notes.
it went pretty slick.
Let us hear how you came out.
Good luck
John

Like yours, mine had the lines turned around to fit the plastic formed packing.
I gently turned them around to the front without problem.That tubing is probably pretty tough, but I treated it gently anyway.
Number 3 has to slip behind number 1 slightly. Position connectors like the technote describes towards manifold so upper half goes on OK,
Details:
http://members.shaw.ca/betterthanyoutoo/Sticking%20Poppet.htm
Between the excellent AF How To and the tech notes.
it went pretty slick.
Let us hear how you came out.
Good luck
John

Hey John just letting you know I got it on everthing seems ok, but I do have one problem that I thought this kit would fix but it's still there . Once in a while it want's to backfire on start up causing the starter to grind. A mech friend of mine said it's proable the crank sensor , ever hear of this problem?

Hey John just letting you know I got it on everthing seems ok, but I do have one problem that I thought this kit would fix but it's still there . Once in a while it want's to backfire on start up causing the starter to grind. A mech friend of mine said it's proable the crank sensor , ever hear of this problem?


Not sure about that one, Terry,
but what do you think about starting a new thread on it in problem diagnosis section and let's see what the pros have to say about it?

John

MFI assembly 12568332
Can someone tell me if the green plastic tubes on the injectors come off. They appear to be too large for the ports.

Terry
Got reply today from GMDirect. You probably heard from them by now.
I picked my parts up from a dealer friend on Wednesday.
Looks like it should fit perfectly, but weather hasn't allowed me to get it on yet. I/m excited about getting that old dog of an injector body out and putting the better design in.
Let us know how you come out.

(from GMDirect)
"pk12568332" is the correct part number for your vehicle, per the VIN
supplied.


Thank you for choosing www.GmPartsDirect.com (http://www.GmPartsDirect.com)


Subject: Part number verification

**Please confirm part numbers and pricing for:

2000 GMC Jimmy 4.3 L Vin 1GKDT13W8Y2103XXX

1 each pk12568332 MFI upgrade

1 each 88894355 V6 Bracket

1 each 17113215 V6 seal kit

Were these 100% everything you needed to order online for this job? Aside from the various tools, are these 3 items all one would need to take this job from cradle to grave, assuming everything went smoothly? I too have a 2000 GMC Jimmy 4.3L, and wouldn't mind doing this job over a weekend to improve my jimmy's performance/economy.

Yep, that's all you will need. I also bought a 1/4 torque wrench from harbor frieght to make sure I got the upper intake fastners installed to the correct in/lb rating (it's freakishly low)- I've heard this is important so you don't crack or distort your plastic intake from overtorquing thereby creating vacuum leaks. Also, buy a couple cans of throttle body cleaner as yours will probably be gummed up from underneath. It's also a good time to think of other stuff to do while you're at it, cap/rotor etc... Before you attempt the job, also check the condition of your lower intake gaskets as these are problematic with our trucks (do a search). If you'd like to replace yours with newer, better designed ones, installing the MFI is almost just a part of re-assembly of that job. Good Luck,

My favorite part about the MFI is the quick starts, two revolutions of the starter every time vs 4-6 with the old poppets! Now it sounds like-*wrowwrowVROOOOM* Actually makes me enjoy the truck more!