StangMuscle

A couple weeks ago my car failed to start in a parking lot. I was fairly certain it was my fuel pump because I was not hearing the pump engage. I tested the volts at the fuel pump (4 ports:2 positive, 2 negative) and it was right at 12v with the ignition on. So.. relay and electrical should be good. I ordered a used pump with 20k on it from latemodelrestorations and I still have the same issue. So im wondering.. did i receive a faulty pump, or could it possibly be the second pump on the passenger side? Would the car run with just one pump working? From my understanding the drivers side pump is the main pump that primes the fuel lines. I just want to make sure I have a full understanding of the system before I return the pump and spend the $ on a new pump.

tx_zstang

There is only one pump, on the driver's side. The wires on passenger side fuel hat are just fuel level.

The driver side connector uses the blk/pk and blk wires (IIRC) as the pump power; it might not be a steady 12v, but could be pulsated.

Check the white wire at the FPDM connector for 12v; that's fed from the inertia cut-off switch. No power there would indicate the inertia switch needs to be reset.

Otherwise, it sounds like your pump is indeed not pumping.

StangMuscle

Thank you very much! Simple troubleshooting.