1990 c4 L98 injector replacement??? how to??
Thread Starter
Intermediate
Joined: May 2004
Posts: 38
Likes: 0
From: Oceanside CA
1990 c4 L98 injector replacement??? how to??
hey all....
i'm thinking of replacing my injectors and wanted to do it myself (since the dealership is out of their mind!! $1695!!) i've never done injectors before, but nearly everything else. not a novice. but, is there anybody that has a good idea of how difficult it is? i have new injectors already.
any comments would be great,
thanks in advance,
gregg aka - flyingVplayer
i'm thinking of replacing my injectors and wanted to do it myself (since the dealership is out of their mind!! $1695!!) i've never done injectors before, but nearly everything else. not a novice. but, is there anybody that has a good idea of how difficult it is? i have new injectors already.
any comments would be great,
thanks in advance,
gregg aka - flyingVplayer
Le Mans Master
Joined: May 2004
Posts: 5,387
Likes: 534
It's a job you can do in a day and with some patience. If you haven't purchased a Haynes Manual or one like it from your local auto parts store, then you may want to. Obviously, the manifold is going to have to come off along with the runners. Be sure to label all the electrical connections that you have to disconnect. Be sure to remove the little cap covering the valve on the passenger side fuel rail and press in the center with a screwdriver to depressurize the fuel rails before you disconnect the fuel lines, which will be right at the base of the manifold a little ways from the passenger side fuel rail. There'll be two lines, be careful not to get them swapped around when reinstalling them, or you'll have a problem. Best to label those as well with their corresponding connections. Having a camera handy helps, if you're unsure of how connections may have to go back. I've done this a few times and I would post up the step by step procedure but I know as soon as I do, someone will just give you a link to a website. 
Last edited by 1985 Corvette; Feb 26, 2005 at 10:54 PM.
Race Director
Joined: Feb 2004
Posts: 12,518
Likes: 19
Ford motorsports 24# injectors are fine replacements for your car. They retail for about $230. Buy an adjustable fuel pressure regulator to fine tune your combo. $100 or less is the cost for these. Replacement involvers removing upper air plenum, loosening runner tubes and removing fuel rail. With rail on bench all 8 injectors are replaced easily. Use new runner gaskets and change the thermostat while you are there. Less than $400 and 4 or 5 hrs time and you will be done. Take the 1,000 plus bucks left and buy lots of beer!
Team Owner
Joined: Dec 2000
Posts: 21,094
Likes: 282
From: Phila., PA burbs
I put 24 lb FMS injectors in my 91 last year and as other suggested the installation was fairly easy. Just be aware that if you go with this injector you will likely need a custom tune afterward. It seems that the MAF cars can adjust for the higher lb injectors, but the SD cars (like mine and yours) don't compensate as well. I fiddled endlessly with my AFPR, but was unable to get the air/fuel ratio where it should be untill I had a custom prom burned.
Thread Starter
Intermediate
Joined: May 2004
Posts: 38
Likes: 0
From: Oceanside CA
hey guys,
thanks for all the help. i did get the dealer to come down to $335. from $499. to install injectors that "I supply" (i got 8 for $189. - new take outs on ebay). $335 didn't sound that bad for the time required to install them. what do you think?? they say it's four hours to do. the cars already there. if i don't do it, i'm looking at $100+ to get it home so i can work on it.
man my head hurts!! i got to go.....
thanks everyone again,
gregg
thanks for all the help. i did get the dealer to come down to $335. from $499. to install injectors that "I supply" (i got 8 for $189. - new take outs on ebay). $335 didn't sound that bad for the time required to install them. what do you think?? they say it's four hours to do. the cars already there. if i don't do it, i'm looking at $100+ to get it home so i can work on it.
man my head hurts!! i got to go.....
thanks everyone again,
gregg
Thread Starter
Intermediate
Joined: May 2004
Posts: 38
Likes: 0
From: Oceanside CA
the great white vette is back on the road!!!!!
hey all,
just wanted to let everyone know that the injectors where the problem all along. 5 of the 8 where really low voltage. the # 7 injector was totally dead. no pulse at all.
thanks to "five O motorsports" in lakewood ca. for the new ford II design injectors ($189) and the dealership putting them in ($335), all is great again.
i had this car into two shops. and nobody could figure it out
go figure!! at least i didn't have to pay for them (no fix-no pay
)
man ... it's good to have her back home in the garage again
thanks to everyone for their sugestions, it's good to have a place to info.
gregg
just wanted to let everyone know that the injectors where the problem all along. 5 of the 8 where really low voltage. the # 7 injector was totally dead. no pulse at all.
thanks to "five O motorsports" in lakewood ca. for the new ford II design injectors ($189) and the dealership putting them in ($335), all is great again.
i had this car into two shops. and nobody could figure it out
go figure!! at least i didn't have to pay for them (no fix-no pay
)man ... it's good to have her back home in the garage again
thanks to everyone for their sugestions, it's good to have a place to info.
gregg
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