its a 93 z28 automatic, so far i have replaced the fuel pump and the fuel pump relay, but the pump still only runs sometimes. Has anyone else had this issue or have any ideas to what it could be, im thinking a bad wire somewhere in the harness or a bad ground somewhere. Any help is appreciated

 

Can you monitor the fuel pump control wire from the computer to the relay and see what it is doing?

 

it either gets power or it doesnt, most of the time i notice it when i go to start the car and the pump isnt running, then other times it will, its a luck of the draw thing. if it does start it will only run for a little while then cuts off, then it wont turn back on until i let it sit for a while