Originally Posted by karpetcm
Actually thats my bad i just have the stock fuel regulator. The car even if i put the pedal to the floor and start it does the same thing as well. I will for sure check the fuel pressure, i actually havent thought about checking the coolant temp sensor i will look at that as well.
I got 93z and I got exact same problem, down to a lot of pressure build up in the gas tank to the point where my fuel pump would whine so hard you could hear it a block away. I would have to turn the car off and open the gas cap to release the pressure, and then it would be fine. I should mention that happened to me only few times though and I don't remember last time it happened. I think that has nothing to do to your long start problem, that is a another issue.
I made threads before and got same advise as you and still I was not able to find answers.
I replaced the following
plugs and wires
Nothing helped. I have played around for years, I would check one thing or replace one thing and still nothing so I would get pissed off and forget it for another year and so on. I didn't want to take it to the shop and get huge bill for it, since it was not a big deal for me anymore.
Then finally, my buddy who is a mechanic who had no answers as well prior to this had me come over to his shop and do some more testing.
He found out that when it was hard to start, the car had no spark or injector pulse. He is not 100% sure because he has not worked on many LT1s but he is certain that its opti spark.
So while you are looking at above, check to see if you have spark when its hard to start. I know that you replaced the opti but still.
Also, do you have hard time starting when the engine is cold? Mine would only have hard starting issue when the engine is warm.
I store the car for 5 months it starts right away, I try to start it after 15 mins of shutting it off it cranks forever.