I've got an '89 RS 305 TBI. I rebuilt the motor this spring and it ran for a few days and then wouldn't any more. I had a mechanic working on it as a side project, but my daily driver broke down so now I'm stranded so I would like to get the camaro running.

What's happening is that I try to start her up and she cranks and the injectors fire enough for her to start, but then the injectors stop spraying and it just dies. I tried revving it a little bit to maybe keep the fuel flowing but it did the same thing.

What could cause the fuel to be cut off? Any ideas? I could really use any advice you guys could give. Thanks.

 

Lack of fuel pressure is your problem i would say.
Since its injected you would have an electric fuel pump which should pressurise the fuel line, but yours probably cant sustain the correct level due to blocked filter etc or if you have a fuel pressure switch etc. This means you have just enough pressure in line to start the car but then not enough pressure to deliver fuel during idling and certanly not enough to plant your foot to the floor. try starting the car but dont increase idle, check fuel pressure, delivery rate etc

 

You need to put a voltmeter in the fuel pump relay system and see if the ECU is turning off the pump, or if you are still sending power to the pump.

if you have power to the pump you need to check the pressure at the manifold, also listen to the injectors to see if they are still openning, or if they are staying shut.

 

also check to make sure that the oil pressure sensor is good. GM computers will spray just enough to get it started then if the computer does not sense oil pressure it will cut off fuel.

 

THe oil pressure switch will not do what you say. It is tied to the fuel pump as part of a redundant system. If the fuel pump relay doesn't come on for whatever reason, the oil pressure switch will turn the pump on when there is enough oil pressure. Disconncet the op switch or the fp relay and find out for yourself.

 

Hi
I found out recently that the ECU will turn off the pump after 2 seconds of cranking if it thinks the distributer is not sending a signal to the ECU. You must be getting a signal to get the injestors to open, so that's probably no help at all.

However it might be worth checking that the signal from the module keeps sending and isn't cutting out and then turning off the fuel.

You need some test equipment for that.