Changing Fuel Injectors
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Joined: Mar 2006
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Changing Fuel Injectors
Hello & Happy New Year to All the C4 Brotherhood ...
I was just wondering if are any secret shortcuts to getting to the Fuel Rail of a 1990 L98 Coupe. I have a couple of bad fuel injectors so I need to get to the fuel rail, so I thought I'd put the question out there.
I have learned so much from all of you that take the time to post a reply. I am a total novice at working on my C4 but since I found this forum, asked questions and learned from the experiences of others, the feeling of doom never enters my thoughts should a C4 problem arise.
Thanks again and all the best for 2009
c4tonezone
I was just wondering if are any secret shortcuts to getting to the Fuel Rail of a 1990 L98 Coupe. I have a couple of bad fuel injectors so I need to get to the fuel rail, so I thought I'd put the question out there.
I have learned so much from all of you that take the time to post a reply. I am a total novice at working on my C4 but since I found this forum, asked questions and learned from the experiences of others, the feeling of doom never enters my thoughts should a C4 problem arise.
Thanks again and all the best for 2009
c4tonezone
Melting Slicks
Joined: May 2007
Posts: 2,171
Likes: 1
From: Warwick RI
I don't think there are any shortcuts but this is definately a "while I'm there" thing. You should do all of the injectors so you don't have to pull the plenum again. It is an odd design that won't allow you to unbolt the rail with the plenum in place.
I am no expert so wait for some more experience to chime in here
Just my $.02
I am no expert so wait for some more experience to chime in here
Just my $.02
Le Mans Master
Joined: Jul 2007
Posts: 5,043
Likes: 8
From: Tampa Florida
No real short cuts that I know of -- it is tons of fun you'll love it....alot about 3 hours or more for the swap....the swap is not hard just takes time.
Tip #1 Make sure that the MAT sensor connector plug back in before you remount the plenum.....don't ask
Tip #2 If your FPR (fuel pressure regulator) diaphram is the "origional" this might be an excellent time to replace it while the plenum is already off.
Tip #3 If you end up with extra parts other than the old fuel injectors and FPR diaphram you'll want to go back and recheck your work.
Have fun!
Tip #1 Make sure that the MAT sensor connector plug back in before you remount the plenum.....don't ask
Tip #2 If your FPR (fuel pressure regulator) diaphram is the "origional" this might be an excellent time to replace it while the plenum is already off.
Tip #3 If you end up with extra parts other than the old fuel injectors and FPR diaphram you'll want to go back and recheck your work.
Have fun!
Instructor
Joined: Jan 2008
Posts: 150
Likes: 0
From: West Newton Pennsylvania
I did my 88 in the beginning of the fall while I was doing the water pump. The injectors where easier than the water pump. The only short cut I found was take off the plenum, and the passenger side runner. You can leave the driver runner in place. While you got it apart, I would change all the injectors, get an O-ring kit for the fuel rails, and install an adjustable fuel pressure regulator and diaphram. Then your done, and may never need to take the plenum off again. Keep track of where all the bolts on your runners and plenum came from, as there are different sizes. When you get your injectors and runners all in place, connect your battery, and turn your key on (don't start car) to pressurize the rail to check for leaks. If there are none, put the runner and plenum back together. I would go with the Bocsh III from Jon at FIC. You will notice a big difference. Good luck, and have fun.
Last edited by jackdk; Jan 6, 2009 at 05:05 PM. Reason: add text
Safety Car
Joined: Jan 2008
Posts: 3,939
Likes: 1
From: Vero Beach Florida
When I did mine I also did a few others things while in there. Check fuel pressure before tear down, if its not right replace FPR while your there, check your EGR for vacuum go over all your vacuum lines. If you have any oil leaks from your covers replace those also easier to remove runners with valve covers off. And to do the job right pull both runners and replace gaskets depending on how long they have been in there you run the chance of having them leak if you don’t. I did a general clean up, by-passed water hose in throttle body, changed thermostat, ect. Remember to test the fuel rail for leaks before you install runners, tighten down rail turn key to on position check for leaks. Oh and get your injectors from Jon @ FIC he’s the best.
Race Director
Joined: Nov 2003
Posts: 12,221
Likes: 446
From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
The only shortcut I know of... is to remove the plenum, EGR, and collapse the fuel rail. You can get it out w/o loosening the runners.
There's a write-up on Vader86's website (done by Bob in St.Louis).
Search for posts by VADER86. A link to his website is under his avatar. Bob's step-by-step procedure is listed there.
Gregg
There's a write-up on Vader86's website (done by Bob in St.Louis).
Search for posts by VADER86. A link to his website is under his avatar. Bob's step-by-step procedure is listed there.
Gregg
Supporting Vendor
Joined: Mar 2008
Posts: 1,762
Likes: 14
From: Cumming Ga
The only shortcut I know of... is to remove the plenum, EGR, and collapse the fuel rail. You can get it out w/o loosening the runners.
There's a write-up on Vader86's website (done by Bob in St.Louis).
Search for posts by VADER86. A link to his website is under his avatar. Bob's step-by-step procedure is listed there.
Gregg
There's a write-up on Vader86's website (done by Bob in St.Louis).
Search for posts by VADER86. A link to his website is under his avatar. Bob's step-by-step procedure is listed there.
Gregg
http://webpages.charter.net/buddiel/...al)%201-04.doc
Last edited by FICINJECTORS; Jan 6, 2009 at 08:21 PM.
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Le Mans Master
Joined: Jul 2007
Posts: 5,043
Likes: 8
From: Tampa Florida
its part of our injector sticky on the top of c4 tech
http://webpages.charter.net/buddiel/...al)%201-04.doc
http://webpages.charter.net/buddiel/...al)%201-04.doc
Supporting Vendor
Joined: Mar 2008
Posts: 1,762
Likes: 14
From: Cumming Ga
its part of our injector sticky on the top of c4 tech
http://webpages.charter.net/buddiel/...al)%201-04.doc
http://webpages.charter.net/buddiel/...al)%201-04.doc
Burning Brakes
Joined: Feb 2008
Posts: 988
Likes: 7
From: Sarasota Fl
I poked holes in a piece of cardboard and made a diagram of the bolt locations. If you do need the bolt lengths, shoot me a PM - I replaced all the old ones and kept a record of the lengths, positions, and thread sizes. It would be a good idea to replace the runner to plenum gaskets too.
Le Mans Master
Joined: Jul 2007
Posts: 5,043
Likes: 8
From: Tampa Florida
Good to go!
He Jon I like the write up.....I like the custom torx set up too......I've used a little different approach with the runner bolts....I used "wobble socket extensions" in conjunction with 3/8" drive torx socket for may years when I run across stuff like this that is too close/tight for U-joint type extensions. These work great and you don't have to mess with the valve covers either. Here is a link of a close up pic of the wobble socket extension I use:http://www.harborfreight.com/cpi/cta...temnumber=5933
They also come in longer lengths....which is what I use most:http://www.harborfreight.com/cpi/cta...emnumber=31203
He Jon I like the write up.....I like the custom torx set up too......I've used a little different approach with the runner bolts....I used "wobble socket extensions" in conjunction with 3/8" drive torx socket for may years when I run across stuff like this that is too close/tight for U-joint type extensions. These work great and you don't have to mess with the valve covers either. Here is a link of a close up pic of the wobble socket extension I use:http://www.harborfreight.com/cpi/cta...temnumber=5933
They also come in longer lengths....which is what I use most:http://www.harborfreight.com/cpi/cta...emnumber=31203
Last edited by engle1147; Jan 7, 2009 at 07:17 PM. Reason: Added the wobble 3/8 not 1/2 drive