2006 Ford F-250 6.0L Powerstroke stalling under load with P0251

Question

I am getting a sudden engine stall whenever I step on the throttle to merge onto the highway. The truck starts right back up after a few seconds, but it feels like it is starving for fuel. My OBD scanner is showing a pending P0251 code and sometimes it goes into a limp mode.

Pete Sanders · Accepted Answer

The issue was the HFCM (Horizontal Fuel Conditioning Module) pump failing. I hooked up a mechanical fuel gauge and saw pressure drop to 15 psi when hitting 2500 RPM. I installed a new Motorcraft Pump (Part # 6C3Z-9G282-C) which cost about $320. After the swap, fuel pressure stayed steady at 52 psi under WOT and the P0251 cleared itself.

hd_trucker_77 · Answer

P0251 on a Ford diesel often points to an electrical issue with the Fuel Injection Control Module (FICM) or the circuit to the injectors. Check your FICM main power voltage while cranking; it should never drop below 45 volts.

wrenchqueen · Answer

Check your fuel pressure at the secondary filter housing. These 6.0s need at least 45 psi at all times; if it drops under load, your HFCM pump might be tired or you have a restriction in the tank pickup.

shoptech_carlos · Answer

Since you are getting a P0251 specifically, look at the IPR (Injection Pressure Regulator) valve. If the screen is torn or there is debris in the valve, it cannot accurately control the high-pressure oil which mimics a fuel metering fault.

2006 Ford F-250 6.0L Powerstroke stalling under load with P0251

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