Hot re-start fuel vapor lock

[tcramstrek]

My 91-ZR1 may have a hot-restart fuel vapor lock issue.... In the Mornings, the Engine runs and performs like normal , I start it up every morning, drive it without incident for as long as I want....that being said it appears the LT5 is running like a Swiss watch.....However after a Hot Engine Re-start if I dont allow the engine to run for two minutes at idle and attempt to drive off again the engine sputters and stammers like it is running out of fuel. ....I am forced to sit in the parking spot until the engine clears itself of this issue and then drive off... I have had this issue as long as I owned the car...

I know for a fact my fuel is new...I keep always fresh 91 octane Chevron fuel in her tank....

[94conv.]

My 94 LT1 is doing the same thing. I can drive for hours and it runs like a top, then let it sit and try and restart within an hour or two and it misses out and falls all over its self. It used to pull its self out of it like yours then one day it didn't. Wouldn't start at all. Had it towed to a chevy guy who I trust (by the time it got to him it would start and only missed out at higher rpms) and he said he narrowed it down the the optspark, which yours does not have. Said he thought if must have carbon striped itself (?) From what I've read up on this happening is the majority seems to end up being the coil has or gets a short in the wiring when its hot. I haven't gotten my car back and it was last wed. when he called thinking it was the opti so it may have acted up on him after he replaced the cap and rotor. Ill post back when I hear back from him.

[John H. Christensen]

91 Octane with 11:5 to 1 compression???????

[Hib Halverson]

The LT5 has electronic fuel injection thus...it doesn't vapor lock.

The problem is also not your gasoline.

Without further information about the problem, it's virtually impossible to diagnose.

Since, you feel the problem is like running out of fuel, have you run the fuel pressure tests in the Factory Service Manual. If so, what were the results?

[Tuna]

I'm with Hib on this one. It sounds like a fuel pressure issue. Check to see if the pressure drops off quickly after shutdown. There is a check valve in the system that may be sticking open when hot that is not letting the fuel pressure come back up to proper psi.