Ok I have 1989 Formula Firebird (350 tpi) I can start it when its hasn't been running for awhile and when it gets warm it will start lopeing and the rpms surge up and down. But if I turn it off it will not start again for about ten minutes. So far I have replaced the Ignition module and the pick-up coil and it didn't really help. I have also checked the timing and its at what the factory says. Also if I try to start it about 5 to 10 times the battery will die. Tomorrow im going to check the tps and the mass air control hope it helps.

 

I had this problem in my 89 caprice. It was a 305 not a 350 tho. Im not totally sure how i fixed the problem tho. I think it had something to do with the pressure in the fuel system(its been a long time). Make sure your getting spark and all that. Make sure none of the wires are rubbing or melted. This might be why when the motor is warm it wont start again. Im pretty sure it has something to do with the fuel pressure though. As a test go ahead and do what you always do to get it not to run. Then unscrew your gas cap...let all the pressure release(1min or so) then screw it back on three clicks. Then see if it starts. If she fires right up then the pressure in your tank is building up to high. Theres a vapor pressure release of some sort. I have no clue how that works. Hopefully some one can add help on that part.

 

The vapor pressure release (check valve) is located back by the tank. Easy to get at - it's the part that comes off the hoses by the other fuel lines. Your TPS and MAF doesn't do anything to help it start. Do you have headers? If so, your starter might be heat soaking. Will need a heat shield over the starter for this. Check the Idle Air Control Valve and clean it off. Let us know when you have done these things. If still happening, let us know and we will think of other things to check.

 

This may be in left field but try a fuel filter. Its cheep so if it does not fix it your not out much.

 

I have already replaces the fuel filter.

 

I am just running stock manifolds but the motor was said to have been rebuilt by the previous owner and I am about to see if it still has the sheild or if he it off. Did they have the sheild stock? Oh and im going to check that valve now.