Thornton98

I recently had my ls1 rebuilt and I have got it all back together and everything done on the car. Problem is, the fuel pump doesn't always come on. First time I tried priming it the fuel pump was coming on and after a while it quit. And then a couple days later I looked around, found nothing and tried it and the fuel pump was working and after about 10 times of turning the key to prime it, it quit coming on. I've changed the relay and the fuse is good. Anyone have any idea of where I could start to find the source or anything to check?

Ollie8974

It is acting normally. Once the fuel pressure is built up, the pump will not activate until the engine starts and the fuel pressure drops.

Thornton98

But only air comes out of the shrader valve. Shouldn't fuel come out if the fuel pressure is built up.

Ollie8974

Hold the shrader valve open. Prime the pump until fuel comes out.

Old Geezer

iTrader: (3)

Once the prime cycle is done, then the pcm sees a tach signal, the pump will restart. PCM is not reading fuel psi as a means to control the pump....