I have a 2004 F150 with a 4.6L. For a while now My check engine light has been coming on and kicking out a code low low fuel rail pressure sensor. The truck on occassion has acted like its running out of gas as well. I drove the truck Friday to work and parked it Friday night. I went out to start it Sunday and it just cranks and thats it. At ht nesame time my battery was shot so naturally the truck stopped cranking so I replaced it and tried starting it again and it would just crank. So I took a gamble and went and replaced the fuel pump on it last night. It still just cranks and wont kick over. On occassion it will act like its going to start and then just continue to crank. I checked the fuse in the fuse box and it's fine. Not quite sure how to test the relay in there and at that the relay sits way back in the fuse box. UI am assuming I can reach it with a pair of needle nose pliers or something to remove it. I did notice that the EVap line that is attached to the fuel pump from inside the gas tank has a twist in it or a kink right below where it connects to the pump. Itried to remove it as much as I could but it didn't help it much. I beleive that line in particular just has something to do with vapor and venting. I am at a loss here as to what to do or even check now. I beleive that you can here the pump prime when you turn the key to on. But the funny thing is if I disconnexct the fuel pump harness iin the splash shield under the drvs door and have someone turn the key to on it still sounds like the pump primes. If it's not the pump them I'm not sure what the whirring sound is back there when you turn the key to on. I am at a loss here and dont know what to do. But this is my only vehicle and I need it. I have already missed 2 days of work because of it.

 

Look for the schraeder valve located on the fuel rail on top of the injectors. Turn key on and off a couple of times to prime the system. Depress the valve (looks like a tire valve), fuel should spray out. No Smoking please! If there is no fuel then go to the filter and remove (special tool) fuel line and re prime. If there is fuel to the filter but not out, replace the filter. On the other hand if you have fuel at the fuel rail then check for spark. Get back to us.

 

Well I think I may have found my problem. That stupid fuel pump drivers module is toast. I unbolted that thing from the rear crossmember and the whole backside of it is dicenergrated. The board on it smells like burnt electronics and there's some black spots on the board as well. I got me another one for 20.00 from the junk yard I will let you know if it fixes it when I get home tonight. I ws going to go thru the dealer and get a brand new one for 100.00 but they said it would take 3-4 days for them to get one and I need my truck now.