I have a 96 f-150 with a 5.8, my problem is that after the truck sits for awhile like over and hour, when you go to start it the fuel pump doesn't kick on, even if i cycle the key a few times. So, it cranks and cranks eventually the pump will kick on and the truck fires right up, if I shut it off and start it right back up it starts as should. It has me puzzled, I've changed the relay and it didnt seem to help.

 

Could be the fuel pump going out itself. If you have dual tank's does it do it on both tanks? I would disconnect the 4-wired plug from the pump on the fuel tank, and check to see if you have power there.

If you do have a front tank, it is far easier to check the front tank wiring than it it is the rear. Could also have corroded/dirty plug connection.

 

It might be easier to hold you hand on the fuel pump relay when someone else turns on the key when it does not start. You should be able to hear and feel it click when the key is turned on each time.

 

i'll give that a try, but why would it only do it after sitting for a hour or longer is whats really puzzling me. and it happens on both pumps doesn't make a difference which one its on

 

Well my guess is a bad computer but did not want to go there yet.

 

I dont think its the computer, cause i'd say it would happen everytime it tried to start, but now after it sits the pump will run for 10-20 seconds shut off, but still wont start. so it'll crank and crank proably i'd said 4-5 times for like 10 seconds then the pump will kick on like normal for a few seconds then fire right up