L98 Idles rough, dies when accelerate
Thread Starter
Heel & Toe
Joined: Nov 2015
Posts: 23
Likes: 0
L98 Idles rough, dies when accelerate
hello! new to the forum! just got an 87 Vette, with the L98. trying to figure out this problem, the engine has been messed with quite a bit. it has extra plugs laying around, but all the important stuff to make it run seem to be plugged in, it turns on, fires up. and it idles, a little rough, and doesnt allow to accelerate, if u try to accelerate it does the opposite and bogs down and eventually dies. the previous owner did say, (which i dont really trust anymore) said the car drove and ran fine before he swapped the the distributor. so i thought it was just the timing that was off, but i checked it and tuned the timing a little and it still does the same thing. checked spark, all 8 plugs spark, although they are black from carbon, when i did check all the plugs, i did notice #3 plug was brand new shiny, which only led me to suspect that the injector isnt working. i have been reading a lot as well, many people say its vacuum, and other say its gas. im pretty sure its gas, or maybe a combination of both, the other day i sprayed carb cleaner into the intake and accelerated and it was the first time i ever heard her accelerate. any ideas what it may be guys?
Last edited by 87L98Vette; Nov 3, 2015 at 11:24 AM.
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Team Owner
Joined: Jul 2004
Posts: 28,475
Likes: 3,291
From: Hartford WI
IIRC they are Multecs. Call FIC to verify. If they are, I'd just toss them and get reman units. Ohming injectors are a poor man's way of trying to get some assurance that the injectors are working. You can't tell if they are clogged and you ASSUME they are working fine because the ohm numbers are good. To me, that test is so misleading, it is worse than nothing.
Team Owner
Joined: Jul 2004
Posts: 28,475
Likes: 3,291
From: Hartford WI
Take the fuel pressure regulator hose off and see if the fuel pressure goes up and to what. If you can, do a WOT run and see if there is a lot of drop off in fuel pressure.
Thread Starter
Heel & Toe
Joined: Nov 2015
Posts: 23
Likes: 0
I got my injector readings,
The noid light confirms all the plugs are working properly, now the ohm ratings on them aren't very good. These are it, numbered by cylinder, also "c" just stood for cold. I don't have hot readings yet.
Injectors
1: 8.3 c 2: 8.2c
3: 7.2 c 4: 7.0c
5: 16.6c 6: 11.7c
7: 16.3c 8: 16.6c
The noid light confirms all the plugs are working properly, now the ohm ratings on them aren't very good. These are it, numbered by cylinder, also "c" just stood for cold. I don't have hot readings yet.
Injectors
1: 8.3 c 2: 8.2c
3: 7.2 c 4: 7.0c
5: 16.6c 6: 11.7c
7: 16.3c 8: 16.6c
Thread Starter
Heel & Toe
Joined: Nov 2015
Posts: 23
Likes: 0
And checked for codes and there are none.
Last edited by 87L98Vette; Nov 3, 2015 at 06:15 PM.
Race Director
Joined: Mar 2015
Posts: 15,926
Likes: 579
I got my injector readings,
The noid light confirms all the plugs are working properly, now the ohm ratings on them aren't very good. These are it, numbered by cylinder, also "c" just stood for cold. I don't have hot readings yet.
Injectors
1: 8.3 c 2: 8.2c
3: 7.2 c 4: 7.0c
5: 16.6c 6: 11.7c
7: 16.3c 8: 16.6c
The noid light confirms all the plugs are working properly, now the ohm ratings on them aren't very good. These are it, numbered by cylinder, also "c" just stood for cold. I don't have hot readings yet.
Injectors
1: 8.3 c 2: 8.2c
3: 7.2 c 4: 7.0c
5: 16.6c 6: 11.7c
7: 16.3c 8: 16.6c
would not evan bother with hot.
Last edited by antfarmer2; Nov 3, 2015 at 06:23 PM.
Race Director
Joined: Mar 2015
Posts: 15,926
Likes: 579