I have a 91 GTA with a 5.7 engine that won't start. I used to hear the fuel pump run when I turned the ignition, but I now I don't. I think (hope) that the relay is the problem. There are three relays mounted next to the master brake cylinder. Two of them are mounted inside of an attachment. One is mounted on the outside. Is the outside one the fuel pump relay? Thanks. Dono

 

Should be. Also the fuel pump relay is more square than the other relays. Are the other two kind of OVAL shaped? If they are they are the MAF power and MAF burnoff respectively. In 91 I am not sure if yours is MAF or speed density. Remember, the fuel pump relay is only used to prime the fuel rail and pressurize the system on starting when pressure has dropped. The power for the pump comes from the oil sender switch assy. It is a parallel circuit, that is that when the engine is running the power for the pump comes from a switch at the sender, not the relay. If your relay is bad you should be able to start the car by cranking it a little more. Usually the starter will force the motor to develop enough pressure to close the switch on the sender. If the pump does not run at all check the pump fuse, that is more likely the best place to start. If is blown, replace it and if the car runs get it somewhere and replace the pump. A common failure is that the fuse pops, it gets replaced and the car runs for a couple of days and dies. As the pump motor starts to go the pump will start to draw more current. Don't overlook a plugged fuel filter either, it will force the pump to work harder and thus draw more current. LOL, Danno

 

Remember, the fuel pump relay is only used to prime the fuel rail and pressurize the system on starting when pressure has dropped. The power for the pump comes from the oil sender switch assy. It is a parallel circuit, that is that when the engine is running the power for the pump comes from a switch at the sender, not the relay.

check out this thread : Mechanic just drove my car with NO OIL! What should I do?
the summary is:
the circuit for the fuel pump is parallel
the relay provides power for priming and when the car is running
disconnecting oil pressure switch will not kill your engine unless you have a faulty relay/ecm
extended cranking should build pressure and provide power to the fuel pump if your relay is bad
jess