Truck Repair: fuel pump, oil pressure switch, fuel pump relay

Question
Why does the fuel pump on my 1992 Chevy pickup
continue to run after the key is shut off? I
changed the fuel pump relay but did not help.
Appreciate any help.
Thank you

Answer
Hello Randy,
My first question is, did the pump shut off while the relay was disconnected?
If it did, then the ignition switch may be the problem.
If the fuel pump did not shut off when the relay was out of the system, then I would check the oil pressure switch, beside the distributor. It runs the fuel pump whenever it senses oil pressure above 4 PSI. That switch might be stuck.

Van