I have a 1988 firebird T/A 5.0 TPI and about once every few months after restarting it when shes hot it would hesitate then die and restart then die. After letting it sit for 20 or so minutes she would start up and run like a bat outta hell! But it turned into every week it and now thats all she does even when shes cold. No check engine light no nothing. I have replaced within the past 3,000 miles and 6 months are
spark plugs
wires
cap/rotor
coil
IAC
vacuum lines
MAF
exhaust (headers also)
02 sensor
Please help I dont want to spend extra money on parts I dont need.

 

I had an issue sort-of like yours this past summer. It would run for about 15-20 minutes then start hesitating and idling badly. After a couple weeks of a steady digression it stopped starting at all. It would start, pop a few times, turn over a few times, smell bad, and quit.

I replaced:
Distributer
Sparks
Wires
Vaccuum Lines
MAP
Voltage Test on the MAP to the ECM
+more.

Turned out to be the gasket around the intake manifold. It had been leaking a little coolant for a while and I guess it finally deteriorated enough to cause a good size air leak.

I was able to keep the car at least running in a sense with the MAP unplugged(throwing it into limp mode so it ran rich enough) and took a can of carb cleaner and sprayed around the seams of the Intake Manifold and runners. Anywhere intake parts touched each other and the engine. when ever I would spray an area and the engine would hiccup i knew it was a leak.

I replaced the intake gaskets (honestly not that hard of a task) and it ran like a champ.

 

Thanks for your reply I just found out it has something to do with the fuel pump. Its loud now and when it comes on the rpms get higher as it comes on and off. Im going to replace that along with the fuel filter and FPR. Wish me luck!

 

Check for codes to. That will be your best bet before you start throwing even more parts and money into it. Wish i would have done this first. But now i know whats the problem, or atleast think i do haha. Theres a way u can get the codes with just a paper clip, just search for it in the threads. Good luck!