okay, i have an 89' rs 305 tbi and i have a few things recently replaced.

First, my problem.. i crank it over, starts right up runs okay for about 10 seconds then drops rpms. surges for a little bit. sometimes it dies after about 10 seconds of running, sometimes after 2 minutes.. ive put in fresh gaskets in all parts of the throttle body because there was some torn gaskets. everything is good now with that, i have done multiple things too my car such as replace:

IAC
TPS
IGN MODULE
CAP+ROTOR
PLUG+ WIRES


i get the feeling its a fuel delivery issue.. ive checked for vacuum leaks and nothing.. I've ruled out everything but Fuel pump, and POSSIBLY an ign module..which was replaced just over a year ago..

 

Yeah, you need to check you fuel pressure, spec is 9-13psi. Auto zone might have a tbi pressure tester you can rent.
Is your tps adjustable?
Make sure your egr valve isn't opening at idle, plug off the vacuum hose for testing the idle.

 

tps is adjustable and i was tinkering with that while my car was running, it didn't fix the problem. i'll check on the fuel pressure and egr. thanks

 

Yeah start with fuel presure. I don't think its Ign Module because they usually fail under heat.

have you checked the fuel filter?

 

how can you tell if a fuel pressure regulator is bad? i was told to check that

 

To check the regulator, first hook up a gauge to the feed side, start it up & pinch off the return line at some point. You might have to add a temp. rubber section to do this. If the pressure goes up (possibly to 20psi) the the regulator is bad. If it doesn't, then the pump is weak, a leak somewhere inside the tank, or the fuel filter is plugged.

 

im having the exact same problem as we speak on my 91 camaro rs 305 tbi.....ive ruled out:
New egr valve, iac sensor, fuel pump (should hear it humming for 3 sec with key turned to on position), plugs, coolant temp sensor, throttle position sensor (TPS), Fuel pump/AC and fuel injector relays, rebuilt throttle body and injectors, fuel filters and fuel lines. My next move is Air Charge temperature sensor. Mine doesn't pull a code any more but it has pulled code 23. which is all leading me to its not getting the proper amount of air/fuel mixture, therefor it surges, dies and/or it feels like its starving for gas when you drive it.

 

I had an issue similar to this not very long ago that may help you out.

My issue turned out to be the Coolant Temp Sensor. Replace it, disconnect the battery, and reconnect again.

https://www.thirdgen.org/forums/tbi/...old-start.html