Hey team, the place i work at has a few f series trucks , im having problems with one of them a 2008 f350 5.4 triton , .ok , it loses fuel pressure .. so i looked at the FPDM and replaced it , when fine for about 20 mins then same thing , got another used module , same thing happened , i threw my basic scanner on it , and fuel pressure was good at 40 odd psi , at idel etc , and would drive fine , as it lost power the scanner showed a complete drop off on psi , so something isnt talking to the module , i replaced a the fuel pressure sensor , checked the inertia switch , i jumped the plug for the FPDM and got 75 psi a full 12 volts , if it stops , i leave it for 20 mins or so and it will start right up , but will fault out shortly after ......i live in saskatchewan canada , im leaning towards the PCM not sending the signal for the FPDM to keep the psi going , anyone have any ideas? , i wont go to a dealer , . i can do the work , also , no codes are thrown at all when this happens , except for when i jump the wires to get it moving , it shows "high pressure at the rail " and it would with a full 12 volts ... cheers for any help
blair

 

I would be looking closely at the wiring between the FPDM and the fuel pump, between the PCM and FPDM, as well as the pump itself. Pumps can act up intermittently.I would also scan for codes. Those problems should set a code if the fault acts up long enough.