Fuel pump/system continues to run..
 

My '90 Mustang w/ a 4 cyl. has a problem. When I turn off my car, the fuel system keeps running. The fuel pump doesnt turn off and listening under the hood you can hear it in the fuel rails cycling gas. This ultimatly leads to a dead battery and probably will get into worse condition. So is this a fuel pump relay or fuel pressure regulator problem? Any help will be greatly apprieciated.

Now sure what would cause that although one thing came to mind, maybe your ignition switch is bad? Try shaking it around while someone listens. I know Ford had switch problems those years causing shorts/fires. Ford recalled a bunch of them.

Just guessing

try your relay, Mine did that a long time ago, I replaced, the relay, the injectors, the FPR, but it wound up being the ECM. Go for the ceap stuff first! Good luck!

Odds are that it's the relay, but it could be the ign. sw. too.

Take care,
-Chris

if it's not the relay sticking then check out the distributer ....on the ford system the computer controls the relay depending on what signals it gets
......when it gets a signal from the ignition it only turns on the pump for a couple of seconds to pressuerize system ,
......after that it doesn't turn the pump on constant flow till it gets a signal from the distributer(telling it the cars running )....there is a pick up in the distributer that sences rotation (its a seperate circuit in the tfi )if the pick up in the distibuter fails it can fool the computer into thinking the car is still running

my 87 did this a couple of times .....i cleaned the distributer out (cotact cleaner and air)and cleaned the contacts for the tfi and it hasn't done it since

Ok, I bought a new relay and now the trouble is that I cant find where it is. The Haynes manual has no luck to it either. I looked under the hood, by the tank, and under the carpet in the back but couldnt find the dang thing. Anybody have an idea?? :confused:

underneath the drivers side seat