jplemons

I have a 03' Supercrew 5.4L I'm having trouble getting it to start.....I was backing up to my dads shop and it died while i was giving it gas. I looked down and the gas cap indicator light came on then went off. I cranked it back up with no trouble and kept backing up then turned it off.... It was off about 10 mins and i went back to start it and it will not do anything but turn over. It won't hit at all....My thoughts are maybe fuel pump? although it has not been making any noises. Or a coil pack.....? also i have a superchip and i tried to read the diagnostics and it said communication error... it has a half a tank of gas and a brand new battery. im going over there in the morning just wanting to know what you guys think or some more things to check out......thanks, jake

jason55330

It could very well be the fuel pump. I would have someone lay or kneel down by the gas tank while you turn the key to the ON position and listen for the fuel pump to kick on. You will hear a buzz sound for a couple seconds while it builds pressue and then the noise will go away. On mine it could take up to 20 times before the pump would finally kick on. So I replaced the relay, fuel filter, and fuel pump over the weekend and it has been running fine since.

Buckcommanderf150

You can also take a rubber mallet and hit the gas tank close to where the fuel pump is while someone is trying to crank it. You may have to hit it several times. I know it sounds kinda dumb but I did it on my truck, my dads truck, and my brothers truck and it got them cranked. It wont fix the problem but it'll get the truck cranked at it'll let you know that its the fuel pump

jplemons

Alright well thanks guys i'll def try that, i'm headed over there now. i appreciate it.

jdf150

If diagnostics are saying communication error, check for voltage at the ecm. Could be a bad relay. If that's the case the fuel pump nor the coils will be firing.

Also check odometer to make sure its reading mileage.

jplemons

well the fuel pump fuse & relay is good, the coils are all reading the same ohms and the primary voltage to the coils is reading the same voltage. I have also heard from a friend about a saftey switch in the passenger side kick panel. He had a problem with it before but that checked out good on mine. Im getting 12v to the fuel pump, but no sounds at all. Since it went out all of a sudden i'm pretty certain its the pump. (my Luck)

Good old Bill

Locate the schraeder valve which is used to check fuel pressure, its on the fuel rail that connects to the injectors. Depress the valve to see if there is fuel present. Fuel should spray out with some force behind it. If no fuel is present then spray some starting fluid into the intake between filter and throttle body. Engine should start.

So basically, if engine starts and then quits, your fuel supply is messed up, plugged fuel filter or electrical issue to pump or the pump itself.

If the engine doesn't fire with the starting fluid, then your ignition is at fault. More experienced help will be required from this point on. Good luck.

jplemons

Finally had a little time to work on the truck today.... I tried starting it again before i tore it all apart and i noticed that when i turn the ignition on not all of the dash lights went off, the four wheel drive and oil light and a few more stayed on and my mileage was just dashes.....? so just for kicks and giggles i hooked up a battery charger and i kept working the ignition back and forth to on and the mileage finally appeared and all the dash lights went out and it started right up. I let it run a min or two then turned it off. tried to start it again ...same thing dashes ------ im wondering now if i dont have a computer problem or like a bad ground. anyone else experianced that?