My 91 z28 will turn on and drive normal but after driving and turning off the car it will not start back up, sometimes it could be a few hours before it will start up right back like nothing and it has start to take a day to turn back on , I can hear the fuel pump and the starter trying to turn Start the car but nothing. I just purchased the car a week ago, the seller told me it could be vapor in the fuel lines since he has kept it in a garage and does not really drive it, sombody else told me it could be the ignition control module. Anybody has had this problem before ??onlu the check engine light and the air bag lights turns on when I try to start it, When it does start there is no check engine light ? When it does decides to work it starts like nothing ever happened

 

When it wont start is the starter turning over and the engine just wont fire or is the starter not even turning? Does the security light on the dash come on and stay on when it wont start or does it go off? Does the starter click when it wont start?
some of the common problems is VATS and also heat soaked starters.
If your starter just clicks after driven I would suspect its heat soaking the starter. Fix for this is new starter and a starter blanket to stop the heat soaking. If the security light comes on and stays on then its a vats issue.

 

I can hear the starter working , no lights besides the service engine soon and the air bags light..... so the car has been sitting in garage the previous owner would drive it a few times a year, I drove it the first night and everything Was working fine and then the second day I went to wal mart and to my moms maybe 10-15 min of driving and when I turned it off for and tried to turn it back on it would not start so I let it sit for about 3 hours and then it turned on like nothing, now it takes way longer like a day to turn on again and it will do it after I park and turn the car off again , also previous owner said he had the fuel injectors replaced like a year or 2 ago

 

Heat related issue sounds like injectors or icm.
do you have spark and injector pulse when this happens.
have you ohmed your injectors warm ?

 

I was thinking icm, they test them at auto zone I will go get it tested

 

I would just test for spark and injector pulse when warm. It may pass testing while cold.