6.0L fuel pressure bleeding down

mchan68 · April 23, 2010

Got one here that is killing me. After installing head studs and a new IPR valve along with fuel pressure regulator, truck will not fire. After cranking and more cranking, and more cranking, I was finally able to bring ICP up to starting specs, but won't maintain fuel pressure. When active commanding fuel pump ON, fuel fills up the secondary housing SLOWLY, but then bleeds back downward as soon as you turn active command OFF. Any ideas? HELP HELP HELP!!!

Aaron · April 23, 2010

Is there a checkvalve in the HFCM?

joshbuys · April 23, 2010

pull the fuel pressure regulator back off and verify none of the seals are rolled/missing....

Brad Clayton · April 23, 2010

Push it back outside and tell them that 6.0L's never break down.

GregKneupper · April 23, 2010

Is it possible that you have a weak fuel pump and when you cracked open the system it cannot maintain pressure anymore?

Brad Clayton · April 23, 2010

I like that, Greg. I have seen that quite a few times myself. Definetly a avenue worth checking out.

mchan68 · April 23, 2010

Well, I just pulled the regulator back off to recheck my work. No issue there. After looking more closely, I notice that fuel will bleed back down the SUPPLY side of the system not the return side. Anyone ever had an HFCM cause this?

Jeff_E · April 23, 2010

Mike,

Are you saying the pressure bleeds down once the pump is shut off? Or are you saying the fuel empties in the secondary filter housing once the pump is shut off?

None of these will hold any pressure once the pump shuts off, but the filter housing shouldn't empty if that's what you're asking. If the filter housing actually empties I'd prolly throw a HFCM at it and see if it sticks. Good luck!

mchan68 · April 23, 2010

Mike,

Are you saying the pressure bleeds down once the pump is shut off? Or are you saying the fuel empties in the secondary filter housing once the pump is shut off?

Yes, the secondary housing empties once the fuel pump shuts off.

Originally Posted By: Jeff_E

None of these will hold any pressure once the pump shuts off, but the filter housing shouldn't empty if that's what you're asking. If the filter housing actually empties I'd prolly throw a HFCM at it and see if it sticks. Good luck!
Well, I just got the OK from the customer for an HFCM. Threw it in, and it fired right up!!!!! Live and learn I guess. THANKS GUYS