I recently bought lwb f150 w/88,000 miles and it runs well when it runs. I bought the truck from the son of the deceased owner. The truck has been sitting for about three years with the exception of an occassional crank up and drive. I started having trouble getting fuel to the engine, so I changed filter and it ran fine for a couple of days and started hesitating again, checked filter and found serious contamination in fuel. I dropped the tank to check pump and tank and found that the inside of the tank was completely rusted. So, I installed a new tank and filter and it ran like a dream for three days. The truck stopped getting gas completely and would not start. Replaced ignition module and still would not crank. I checked the pump and it was running, but no very little pressure at shraeder valve. Dropped the tank again to check out pump and found torn diphragm. Replaced fuel pump with aftermarket pump. The truck still will not start and there is no pressure at all. Also there is no fuel coming out of line even though the pump is running. Any and all comments and info would be greatly appreciated.

The rear tank is not working either and I am wondering if that has anything to do with front tank problems??

I am in process of getting shop manuals but could desperately use some input.

 

bump.............

 

Check the fuel rail regulator.

 

It is possible the rear FDM has bad valves in it.
Did you replace the front FDM or just the fuel pump?
Not very many owners just replace the pump and it could also have bad valves.

 

thanks for the responses.

I replaced the front FDM. I haven't checked the rear FDM yet. The truck has been running without the rear tank for a while, atleast as far as I know. Is it possible that the valves just went bad and does that affect the pressure of the front tank and FDM. If so, does it make sense to replace the rear FDM or is it possible to disconnect the rear tank?

Also, can the fuel rail regulator be affected when no fuel is even getting to the regulator?

Once again, any and all responses are welcomed.

 

I don't know how the valves are design, but yes it could effect the pressure. Like leaking the pressure to return. I f it was leaking to the other tank you should see a tank level change if run long enough.

If the fuel rail regulator (valve) is open you will not build pressure.