1991 f150 4x4
the fuel pump runs and will not shut off. 60 lbs psi at the engine. replaced the relay and pump does not run at all

 

hey, i am new to the truck game but i have had a few mustangs that had this problem with the relays... and i am aware that the wiring is different between the stang/truck but with the mustangs there are a few different relays not just one that controll the pump, i had to run between ford dealers looking for relays for a week, i changed one then and another would screw up, I would find out if the truck has the same relay set-up as the stang... and this is probably no help at all but i thought i'd try
~have a good day~

 

I had the problem of the pump running all the time. I replaced the relay and the problem was solved. On my 1990 f150 and my 88 bronco ii, the fp relay is on a green plug, is that the one you replaced? You say not run at all, do you mean the truck will not run? Or does the pump not run when the ignition is on and not running? The fp should run for only a few seconds when you switch the ignition to run. Once running, it should run continuously.