Hi im new to the forum, and would appreciate some advice on my new vette. its a 1987 coupe with a stock L98 no mods on the car.

the issue im having is very confusing so ive decided to come here to look for some help from some of you with much more experience.

1st problem im having is my car doesnt start, the engine turns and it cranks and sounds as if it will fire up then just does nothing, only way to get it up and running is if i floor it and crank it then it runs. i dont think this is the best way to get around with it so i have stopped driving it till i can find out what the issue is.

2nd problem is when i do get it up and running, i have to work the gas pedal continously to keep it from dying, and if i shift it down to R it just dies out if i dont floor it lol so im like driving like a mad man in reverse, trying to keep it going.

i have codes pulled out from the car, they are 21, 33, and 44. i believe its regarding the tps, o2, and maf sensors. i replaced the tps about 2 weeks ago was working fine till now i guess with the starting up issue, just recently got the fuel filter replaced thinking it was old and clogged up but still doesnt fire up, im looking to check and replace the fuel pressure regulator next, also on the intake manifold i see what seems to be coolant or oil leaking could that be from the gasket(green in color)? anyway any advice tips is welcomed and appreciated, if u need more info on anything from my car just let me know, im not that savvy on this car stuff but been working hard to figure out this issue for a couple weeks now. thanks.

 

i have a similar issue. Mine wont start unless foot flat to the floor and crank. Mine will idle though, Would be interesting to see peoples opinions. I have no codes or SES light on.

 

Sounds like the fuel injectors to me! When's the last time it had a tune up? (plugs, wires, rotor and distributor cap?)

 

Sounds like a LOT of fuel for a leaking injector. I bet a ruptured FRP diaphragm.

 

ive just recently got the car for a couple months, i knew it was gonna require quite a bit of work when i bought it for a very low price, but im looking to get it tuned up either this weekend or early next week. ill get the fpr replaced in a couple days and let u guys know what happens from there. ill test out the fuel injectors and check the lines to see for any problems as well. thanks, c4.

 

Sounds like your not getting air and that's why it starts when you depress the gas peddle, which opens the throttle plate. Do you have an FSM?

To check the IAC, unscrew it from the throttle body and have someone turn the key, but not start, while holding the pintle. When power is applied to the IAC the pintle should retract all the way then return to the set idle position, which I believe is 1/8" from the gasket surface to the tip of the pintle. Check this.

Then ensure your TPS is set to .54v to .60v with the throttle in the closed position. If these two are good, set minimum idle.

If these are set correctly and the problem persists, check fuel pressure and ohm injectors.

You do need to find out what your leaking and from where and research your codes. On my 88 they are:

Code 21- TPS Circuit Signal Voltage High
Code 33- MAF Sensor Circuit gm/s high
Code 44- O2Sensor Circuit Lean Exhaust Indicated.

Good luck!

 

Say....WHAT?? Maybe it's your air pressure regulator then...

I'm going to go ahead and say that I bet he's getting air. It is MUCH more likely that he's getting way too much fuel and he should start diagnosing there. Let's not confuse the guy w/highly unlikely scenarios.

 

If there is green colored fluid leaking from the intake manifold it might not be (and probably isn't) excess fuel. Is there any white smoke coming out the exhaust when you get it to run? You might just have a leaky manifold gasket and hopefully not a cracked head. Otherwise, the fuel pump, fuel pressure reg. or TPS are the most likely suspects. I'd check the TPS, and Fuel pressure at the rails first.

 

Code 44 O2 senses lean exhaust.

 

well thank you all for your inputs, i just wanted to come back to state the resolution to my problem for anyone else who might encounter the same issues, it was the idle control valve had it replaced, and the car has been running great for the past couple weeks and the tune up was a great addition, wish i had done it sooner but alls well, ride on. C4 Dynamo