OK, here's the deal. my brother-in-law's 91'Z L98 car will not start when hot. We replaced the ignition module about a week ago, and it seemed to help, but it's back to it's old ways. What it usually does is, starts fine when it's cold, but after it's driven, it will not start for about 30 minutes. That was until yesterday. He was driving the car up here to Clarksville, TN from Little Rock, AR, and he pulled over to get some gas. He knew that car probably wouldn't restart if he shut it off, so he left it running while he filled up. Well, after he filled up, when he got back in the car to go, he put it in drive, and when he hit the gas pedal, the car stumbled and died. Obviously, it would not restart after that. He says here recently he doesn't believe his fuel pump has been sounding right, as when he turns the key to the on position to prime the pump, he'll hear the normal buzzing sound, but then a gurgling type noise right after that. He also says the car has been driving pretty crappy lately too. At part throttle, the car drives fine, but if he tries to make an WOT passes, he says the car will stumble, hesitate, spit, and sputter.

At first, I thought his non-starting problem might have been electrical, due to the fact that it only happened when it was hot, but now I'm thinking it may be fuel related.

What do you guys think?

 

I just had this happen to the IROC - the coil overheated and I had to wait for it to cool down before it would start again. I heard later that there was a recall on some GM cars for this problem. Not ours of course.

 

Is it a problem in the wiring you think?

 

I just realized - got bit by it once before - you have a 91 which is a coil pack setup. Maybe you got a bad ignition module for it - or - maybe there is a wiring problem that causes it to blow out easy.

 

Sounds like a bad coilpack to me

 

You have headers on that thing? My starter, located just below the passenger header, got the starter so hot after about 25minutes of driving it wouldnt start again until it cooled. I got a starter with a heat case shell and starter blanket. Solved the problem right away.

 

Yep, he's had SLP's and ORY on it for over a year now without a problem.

I'll check into the coilpack.

 

Is the engine turning over at all? If it isn't then it's almost for sure the starter solenoid. It could very well take a yr for the starter to show signs of heat-soak. Look into this first!

 

I had this exact problem, for me it was the starter "heat soaking" from my headers.

I bought a heat resistant wrap made for the starter for $25 and solved my problems forever....

Hope your fix is this easy.

 

The car turns over fine, it just will not catch any fire.