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

Mark

 

Sounds like your HFCM to me. Does it fill up the bowl with the filter out and key on/engine off?

 

I can check.....Happened this morning while the wife was driving it. I stopped to look at it after work and tried to jump it back to life but had no tools. Used an ink pen to check for pressure at the schrader valve. In truth I had no idea that valve was there until I started diagnosing the issue. My dashDaq monitors the rail pressure signal but I have no idea where that happens in the system. Logically it has to be after the HPFP and with my low readings I'm unsure which is bad. If the HFCM isn't delivering fuel at a significant pressure it would seem logical that the HPFP would not try to pump an insufficient volume.

I looked as close as I could at the HFCM and i appears that there are three bolts holding it on and possibly the front drive shaft will have to be dropped from the transfer case. Other than that I've read the fuel lines can be a pain and I'm not looking forward to cracking the factory seal on the disconnects. Other than that it looks pretty easy besides the fact I will be doing it in a grocery store parking lot.

Any advice is welcome....Thanks

 

The HFCM is very easy to replace. 3 13mm bolts hold it on. Lines aren't bad, just find where the tabs need to be pushed in. If you have to replace it of course.

 

This PDF will help. I'd also suspect: air in fuel system, control valves, sensors and microbial crap in fuel tank. So, I'd bleed the fuel system ... check on youtube for video. Then, I'd use bio kleen in tank. Check filters again and continue to eliminate possible causes. I would think the HPFP would throw a more typical HPFP code. I would also think a misfire would throw one of the misfire codes. So, your probably right about the lift pump but I thought early signs of a bad lift pump would be a misfire/rough engine when towing a load (high demand). I sort of recall that the high pressure pump could suck fuel from the tank under modest loads, which would disguise lift pump problems. Got some great diesel techs on this forum and you should hear from one of them soon. Best of luck.

 

Removed the engine top filter housing and keyed the ignition on. Bowl was half full and filled up quickly.???????????

I'm very mechanical and at 48 years old have never had to take a vehicle, boat, atv, motorcycle, digital camera, computer or chainsaw to a dealer yet.......this may be the first.

 

When was the last fuel filter change? OEM filters?

Did you properly follow the process for bleeding air? Running low/out of fuel can cause HPFP failure...

 

Thanks for the replies so far........

Yes, OEM filters from the dealership.......changed 4000 miles ago. I buy my fuel from two different stations and both are newer construction with tanks that are less than 10 years old. I use PS Diesel Clean most of the time.

I'm certain this is a fuel delivery issue. I'm looking for the differential diagnosis process to determine which part or parts are the cause.


Thanks

Mark

 

Hey gang, I appreciate the feedback. But I am truly looking for a Ford mechanic that has done the differential diagnosis and can tell me which part this is. The HPFP or the HFCM?, and which tests to use in the diagnosis. I know you gentlemen are out here, Please Help................It will help many others avoid the 8000 repair,

 

FATBOYTX.....Thanks for the pdf. Theres a lot of info.

Called the dealership to tow it away and diagnose without repairing it.will probably post back the results.

Anyone else had this issue?

 

Three injectors out. Dealership says it will need a oil and filter change as well. $2,800.00.

 

That sucks.

 

My bad....came to 2300.00 for the injectors and the passenger power window has been broken for awhile now, 400.00 and new batteries 299.00. Cool three grand. Gotta love a diesel.