Hey guys,
Let me start off by saying that I have learned some much off of this site. So thanks alot. Now to the question.

Myself, and my father are restoring his 1990 Formula with a 5.7 350. A little while back, he had it in pepboys, b/c it would stall out, and being that its fuel injection he found that odd, so we took it to them. They came back and said, our fuel pump needed to be replaced, and it would be $400.00. So my dad laughed, and walked away.

So later that day, he went out to start it, and the battery was dead. So he got a hot shot, and drove home. When he got home, he took note, that after he shut off the engine, the fuel pump continued the run. So he took a hammer, open the hatch, and hit the area about the fuel tank and it shut off. So the next morning, he gave it a shot, and the car started. So then he shut it off, and the fuel pump went off. So everything was ok again.

So about a week later, he shut off the car, and the pump was running, so he pulled its fuse and it stopped. And he replaced the fuse, and its ran fine ever since.

I'm sorry for the oong post, but just wanted to give some background. So now, it doesn't do it, but sfter we shut off the car, the pump runs for a few seconds longer, then shuts off.

So my question is, does it sound like the pump need to be replaced ???

Thanks for everything, if you have any questions, just shoot me a pm or a e-mail. thanks for everthing guys.

~Drew

 

There are two circuits that run the pump. The ECM triggers a relay that will turn it on for a couple seconds to start the engine, then when it (the ECM) gets an RPM signal from the distributor it turns it (fuel pump) back on as long as the engine is running. Now, as a back up circuit there is an oil pressure switch that also puts power to the pump, and when you shut off the engine, this pressure switch will keep the pump running for several seconds until the oil pressure drops to near zero. A car that has really good oil pressure, or a cold engine, will cause the pump to run for a while, but it should shut off eventually. So, I'd say if it is running on, you have a sticking relay, or a bad oil pressure switch, but be sure it's not just running normally with oil pressure.