92 zzz28

Lately my fuel pump has continued to run after the engine is shut off and the key is taken out. I tried varies procedures to stop it from running with everything off. It did this once about a year and half ago, the sucker was running when I came out to my car in the morning, it DID go off when I turned off the car the night before.

Tonight, I went out to my car to get something and I heard the pump running. It DID go off after I got home this afternoon and it WAS NOT running a couple hours after that when I went to get the mail. Any thoughts? My first guess is the relay. The only thing that erks me is that last week when this happened, I unplugged it, and the pump contiuned to run!! Help me please.

8Mike9

My guess would be the auxilliary oil pressure switch is sticking, not sure where it's located on your '92...someone else will chime in.

92 zzz28

I don't have an auxillary oil pressure switch that I am aware of. I only have one and it is above the oil filter and it is a fairly new dealer item. Thanks for the reply.

ZZ28ZZ

The fuel pump gets power from the fuel pump relay and the oil press switch. They are redundant. Either one can run the pump.
I assume you unplugged the relay and heard the pump still running. If that's the case, your oil press switch must somehow be supplying it power. Next time, unplug the oil press sw. and see what happens.

92 zzz28

Yes, I did unplug the relay and the pump did still run. I find it weird that the pump seems to have the ability to come back on when the car is already shut off. Last night, the car sat for a few hours and then the pump came on. I know it came back on because I was outside a few times and it was not running. Thanks for the reply.

92 zzz28

Well, I think you guys were right. Thanks. I woke up to a dead battery this morning. I put my charger on it and the fuel pump was still running, I guess it ran all night. I took your advice to check the oil pressure switch. I unplugged it and the pump shut off. I got a new one form the dealer and installed it and so far the pump is staying off when it is supposed to. I appreciate the info.

kane91z

i just had the same thing happen tonight - i finished my 350 swap - came back 3 hours later (after the car had been off) and the pump is going full blast - so i just unplugged it (fuel pump) ill check the relay - I assume this couldn't be due to a leaky injector or such since the Ignition is off - there did turn out to not be a plug in my oil sending bypass - i tried to finger tighten a freeze plug into it and its not leaking - anyone think that could be the problem??

my car has been apart for nearly 2 years - any other possilities it might be?