well i finally got my 94 z28to run after a new opti install. It will fire right up on the first try when cold and run fine but as it heats up, it gets harder and harder to start after i turn it off. It will get to the point where it wont start at all but will sound like it is trying, it sounds almost like run-on or something but while i am trying to start it rather than turning it off. But the car will run fine until i turn it off. When i try to restart is when I have problems. I can wait a few minutes(3-4min) and try it and it will usually start. I know the plug wires are routed correctly, i found no vacuum leaksand i have no codes.I replaced the plug that comes from the main harness to the opti harness with a new 4 pin weather pack connector b/c i found that it wasnt making good connection, i could wiggle it and the car would die. I thought this was my problem but after i replaced it i still have the starting issue.
Anyone have experience with this type of problem? i will be thankfulfor any help you can give.

 

i found another symptom! if i blip the throttle half way the car will choke off and die.
I can stomp it wide open fast and closed again it wont die.

 

Only thing I can think of is to check/clean your injectors and make sure you have good fuel pressure. Also check that your throttle position sensor is giving a good reading.

 

yea i have to get a new fuel pressure gauge, my old one broke. I can watch it with my scantool while it is runningand i dont see anything out of wack.

 

it does look like my o2 sensors are hanging on the lean side not switching over .450, im going to try a little propane and see if theyjump to .9

 

hey this is if u have headers.. ur headers will heat ur starter up and it will make it hard for it to work i had a 95 and it did this to me i went to napa and just bought thier best starter and it fixed my problem for starting...