1989 camaro rs with a 305 tbi changed the fuel pump and relay and will start but will only stay running if u butterfly the gas pedal so could the problem be the fuel system or elsewhere pleasehelpthx?
If it was running okay before you put the new fuel pump on, try this.......disconnect the negative battery cable and let it sit for 15 minutes. During that time, open the throttle body and make sure the blade is closing all the way except for the tiny gap which is to permit the car to idle. After 15 minutes or so, reconnect the battery, and start it.
If this doesn't make a difference...did you also change out filter when you changed the fuel pump?
If you did, did you put it on to flow the correct way?
If you didn't change the fuel filter......change it now.......a lot of junk gets sent to the fuel filter when you change out the fuel pump.
Also try your map sensor this regulates the amount of fuel pressure to the inside of your manifold to be the same outside. The Throttle position sensor is also a culprit of this symptom.
I have the same car and mine did the same. I tried a new map sensor and that didnt work... Needed a new intake manifold gasket... Later it started again and would only idle if you kept the RPMs up, replaced the alternator and now it runs like a champ
I had a similar problem that would only happen when the engine was cold. it was a bad temperature sensor.it wouldn't raise it own idle to warm up and would want to die right away.