I need help bad!!!

I have a nice black 89 formula 350 TPI that I love but is driving me insane. It will not start unless I spray a carb cleaner into the intake but once I do that it starts and runs beautifully. After I start it I have no problems and if I turn it off and let it sit for 20 min when I go to start it, it starts up but if I let it sit for too long (2-3 hours) then it wont start. Also if I start it and turn it off and then try starting it right away it will not start. It cranks and sounds like it wants to start but wont unless I spray the carb. I have two different GM dealearships look at it and they cant get it. I have had the computer, distributor, starter, and idle thermometer replaced and each time I bring it back from the dealer it works great for a couple days then just sinks back into its normal routine. Any suggestions would help.

So, it is a TPI but has a carb? Or you are just spraying carb cleaner into the intake tract?

It doesnt have a carb I just spray the carb

sounds like a fuel pump to me. But it is TPI right? not a carb?

Yea it is a TPI no carb. and both places I went to said it wasnt the fuel pump

replace the fuel filter.

I did that too and no luck

I ran out of carb and I am spraying starting fluid now so any kind of either will get it started

did you check power to the fuel injectors? are they cloged?

so youre getting spark and fuel but no power? try check those two.. when you start it up toss a lot of fuel system cleaner into the tank, maybe that'll clean the injectors, make sure youre getting power to them also.. it seems like you are since it starts up fine once you get it running.. its weird that it'll run once its started but not before..

Maybe a leaky gasket. Or some type of PROM problem. Could it be the IAC or TPS?