1993 Chevy P30 fuel pump help

More To See wrote:
If in fact the engine quit running when you put it in park that would eliminate the fuel pump relay. That relay is completely out of the circuit when the engine is running.

(So if you are ever out a hundred miles from nowhere and that relay fails all you have to do to get the engine started is to unplug it and temporarily jumper across two of the connector pins on the harness. Pin A is 12 V & Pin E supplies power to the pump. Only for a couple seconds though till you get the engine started. I'd be a bit careful in that connector. The computer is on Pin D to pick up and drop out the relay. Pin F is the relay coil ground.)

That entire fuel pump circuit is 12 V. The wiring diagram says it is picked up from the Ignition source by a 20 amp fuse and then sent to the fuel pump relay and to the oil pressure sending unit - on two entirely different wires. (I've never found that 20 A fuse on my rig, though. It must be picked up somewhere else.)

Back at the tank on the driver's side there is a gray wire in a somewhat small harness carrying that 12 volts to the pump.

If you want to check to see if that 12 volts is available when the key is turned on go down to the oil pressure sending unit and unplug the connector. One of the three pins should have 12 volts on it. I'd replace that sending unit just for the heck of it, too. They are cheap ($25) and that's all that keeps your pump running when out traveling around.

(The fuel pump start relay is a $10 item.)

Have fun checking things out. Better at home than parked out along some long lonely road - - at night in the rain.