i think it is air temp sensor heatsoak. the sensor is located in the bottom of the plenum. after shutdown the heat in the intake goes up into the plenum. that is one of the reasons racers ice the plenum in between runs. what i do is just hold the gas pedal down about 10 seconds before i restart the motor. try it. i hope it works for everybody.

 

I'm having the same problem with my '87 but when it's hot after having started fine when cold, when I turn the key, it doesn't even get a click from the starter solenoid but all other electrics run fine. If I let it set for maybe 15 to 20 minutes it starts right up. Anyone have any ideas?

 

I've found a fix for my particular problem. I decided to take the least expensive path to correct the problem and it worked for my '87.

I bought a role of heat tape from the local parts store and wrapped the wire coming off the small post of the starter solenoid that is, the post nearest the engine. I cut small, 6' pieces of the tape and wrapped the wire with two layers of the tape. Yes, it is quite tight in there. I wrapped from the terminal on the solenoid, up as far as I could, maybe 8'-10".

I've now tested the C-4 several different days, all of which have been above 90 degrees, and have run the it for an hour or so with the water temp 200 - 220 degrees, brought the car home and, it started up just like it is supposed to.

This is not to say that others of you may not have injector leak down problems or some other things but why not try the cheapest easiest way to fix your problem? I worked for me.

Incidentally, I recently bought a 2001 C-5 and see the wiring harness on it is also wrapped with the tape. I don't know if all C-5's are wrapped or not, but if they are, maybe this is a problem that Chevrolet recognized and fixed on the C-5's???