HPFP or HFCM

[sailmfast]

Here's my story, I know someone here will know the answer:

4000 miles ago my 6.4 was surging when cold. Blamed it on the cold and changed the fuel filters. Problem pretty much went away. Still felt some minor surging but couldn't tell if it was a fuel issue or just the extremely touchy peddle from my Spartan tune. Today it died in traffic. It was low on fuel and I assumed it ran dry. Got it fueled up and drained the battery trying to refill the HFCM to start it. Now with a good truck to jump it I only get a fast crank and the sound that reminds me of a gas engine with no spark.

Codes are low fuel rail pressure and low fuel pressure at the injectors. I have fuel at the schrader valve on the HPFP but no change in pressure when cranking. I also show only 195 psi at the rail when cranking and I know it idles with around 5000 pounds. One other thing, the high pitch wine from the HFCM can not be heard when cycling key on. I can feel a vibration when touching it but it is nothing like what I'm used to. I think its the HFCM but don't want to throw an expensive part at it.

For reference I have had Spartan tunes in it for the last 45,000 miles and never a problem. I run the +250 for the noticeable improvement in mileage and am not afraid to drive it hard once in a while. Recently changed it to the +125 because of the touchy pedal and poor tire lifespan.

Anyone have experience with this issue? Any way to diagnose for certain that it is the HFCM? Thanks for any advice

 

[Powerstroke Man 6.4]

Here's my story, I know someone here will know the answer:

4000 miles ago my 6.4 was surging when cold. Blamed it on the cold and changed the fuel filters. Problem pretty much went away. Still felt some minor surging but couldn't tell if it was a fuel issue or just the extremely touchy peddle from my Spartan tune. Today it died in traffic. It was low on fuel and I assumed it ran dry. Got it fueled up and drained the battery trying to refill the HFCM to start it. Now with a good truck to jump it I only get a fast crank and the sound that reminds me of a gas engine with no spark.

Codes are low fuel rail pressure and low fuel pressure at the injectors. I have fuel at the schrader valve on the HPFP but no change in pressure when cranking. I also show only 195 psi at the rail when cranking and I know it idles with around 5000 pounds. One other thing, the high pitch wine from the HFCM can not be heard when cycling key on. I can feel a vibration when touching it but it is nothing like what I'm used to. I think its the HFCM but don't want to throw an expensive part at it.

For reference I have had Spartan tunes in it for the last 45,000 miles and never a problem. I run the +250 for the noticeable improvement in mileage and am not afraid to drive it hard once in a while. Recently changed it to the +125 because of the touchy pedal and poor tire lifespan.

Anyone have experience with this issue? Any way to diagnose for certain that it is the HFCM? Thanks for any advice

Had the same problem ordered the low pressure pump in the HFCM from dieselfiltersonline.

Truck had a loppey idle when first started put a gauge on it making good pressure. Gave out a few days later.

http://powerstrokearmy.com/forums/showthread.php?t=63391

http://www.dieselfiltersonline.com/...embly_replacement_pump_kit_f_series_6_4l.html

 

[DEEZUZ]

You may have cooked your HPFP and sent debris into fuel system. One time running low on fuel will do that

 

[Lipka101]

You may have cooked your HPFP and sent debris into fuel system. One time running low on fuel will do that

May have. But that's worst case.
OP It probably is the hfcm but I don't know how to test it. How much pressure do you have at the schrader? I would make this my excuse for upgrading the low pressure fuel system.

 

[White_monster]

Bleed the fuel system properly before cranking. Crank a banjo on the fuel cooler, rear banjo, and cycle the key 10 times. Then fire it with the fitting loose and once running tighten it. Let it run and bleed air out on its own. If this, doesn't work you gave other issues. Start with simple free stuff before throwing money at it. It will not bleed air out through the schrader valve FYI.

 

[DEEZUZ]

Is she hitting in 1 cylinder when cranking also? I'm kinda thinking maybe a stuck injector... pull the DP and look for a ton of thick dark smoke while cranking. Could be washing down a cylinder and causing low rail psi

 

[sailmfast]

Sorry haven't been back for awhile to check the responses. I was in a position where I had to have it fixed quickly. Towed to the dealership and they diagnosed and replaced three fuel injectors one of which apparently failed open. Pumps are fine. Wallet is $2300.00 lighter however. Thanks for the input and advice.

 

[cccj]

Is she hitting in 1 cylinder when cranking also? I'm kinda thinking maybe a stuck injector... pull the DP and look for a ton of thick dark smoke while cranking. Could be washing down a cylinder and causing low rail psi

I have a no start situation and this sounds like what mine is doing. About 1 cylinder is hitting with a ton on black smoke when it hits. Rail psi is all over. No codes.

 

[DEEZUZ]

Just to get the truck to move I have been able to cap the rail and start and run it.. didn't want to put in a new injector only to have it be contaminated.