Brettov

Hi I'm new here . I have a 89 F150 4X4 . With the 5.0L . When i shut the key off , the in line high pressure pump keeps pumping .It will stay on until the batterie goes dead . It seems to run just fine when i drive it . Do you think it's the pump itself or something eles causing the problem . At $100 i don't want to just put in a new pump if thats not the problem .

nohsp4u

My Factory manual does not go back to your year, but on my 91 i have a fuel pump relay and a battery saver relay. Check your owners manual, if you have these check them, best way to check, see if you horn relay is the same, if soon hit the horn, if it works, good test relay. If bad about $6.00 new for part. Let me know if it helped.

dockman

I have the same problem, also an 89, 4.9L. Let me know if the relay test works. thanks

Brettov

Thanks for the tip . I will check it out this weekend .

dockman

I think I got it fixed. I pulled the relay wiring clip off and the relay out to find out which one I needed (apparently there are 3 different ones). The parts store didn't have it, so I put the old relay back in. Problem solved. The relay either had some water get in and freeze, keeping the contacts energized, or there was a bit of crud in there. Either way, pulling the relay out and re-inserting it cleaned it out and now it works fine. One of the mechanics at Pep Boys told me that happens a lot, though usually it damages the relay and you have to replace it. Hope that helps anyone with the same problem. At least it's a starting place if the truck is drawing fuel the way it's supposed to, yet keeps running when shut down.