Hi,

I have a 1990 mustang GT hatch and was driving it one day and went to shut it off and took the key out. Now I have the key in my hand and the fuel pump is still running and won't stop. So I disconnected the battery so the pump didn't burn up, but I can't drive it anymore till I fix it and I don't know what is causing this problem and how to even start looking for it? Can anyone help me?

Thanks

Talking with the guys here, it sounds like your fuel pump relay has failed. This would cause the pump to run all the time. Let us know if its giving you any other symptoms, but that should take care of your problem. I posted the part number of the fuel pump relay from our site. -Karson

lrs-9345a

Just in case you didn't know where the relay is...on 91 and older cars it is under the drivers seat and on 92-93 models it is under the hood by the air inlet tube by the mass air meter.

Thanks guys for the info. I thought that wa my problem but wanted to make sure. And No Scott it is under the passenger seat in my car. Thanks Karson for the part number because that is pretty much what I was looking for, but is that a part number for ford?

Thanks Again

Did the relay fix it?  Usually, you can just swap relays and see if that works.  If it doesn't then you may have a fuel pressure regulator problem OR you may need to replace your ECM.  All those can keep your pump in prime - just not with key off - engine off.  So, it probably is the relay.  Just wanted to know if that was the fix.