so far I checked for spark had it running with starter fluid, replaced fpsm above spare tire, changed fuel filter, checked fuses and relays... wasn't able to get it to start for 4 days then I tried the old rubber mallet to the gas tank trick then I could finally hear the fuel pump turn on, had it running a few minutes nice and strong, but then I let of the gas and it died, I banged on fuel tank again till I heard the weak sounding fuel pump turn on, was able to get it started again didn't run as long as the first time, is this a sure way of telling its the fuel pump, or should I still check something else first? thanks in advance

 

What year is the truck? If corrosion is a possibility, you might want to check the FPDM before replacing the fuel pump. Here is a link.


https://www.f150online.com/forums/ar...placement.html

 

already replaced it, still no luck ... bout to go take the truck bed off

 

I think you'll find it easier to drop the tank out the bottom - even if it's full. Removing the bed - unless you have access to a lift - is a bit of a pain.