Ford 6.7 Low Fuel Pressure

[scottz]

I know this have been beat to death on the Ford forums, but thought I would toss my experience in and get some advice. Last Sunday (of course on Sunday!) I has about 100 miles north of Denver, heading home towing my 5th wheel; about another 450 miles to go. After topping off with 19 gallons of diesel (tank was just under 1/2) I pulled back onto I-76 and before I got to the end of the on-ramp I got the "Low Fuel Pressure" warning. I continued a couple of miles to the next off-ramp; by the time I got there I had "reduced engine power", codes P008A and P0087 via my TorquePro app, a loud whine (low pressure pump?) and a rough running engine.

So, I'm sitting beside the interstate on Sunday afternoon trying to figure out what to do. The only option I really had was to change the fuel filters (I carry spares and tools). I drained fuel from both the OEM filters and my Donaldson filer (I have a Donaldson fuel/water filter separator prior to the OEM frame filter) and there was only a few drops of water from the Donaldson. After changing both OEM filters, I cleared the codes, the truck started right up (no whine) and never missed a beat for the 450 mile trip home, including going over Wolf Creek Pass.

So, what happened? I suspect that air got into the system, but how? It ran fine for about 6000 miles since my last filter change. Did re-fueling have anything to do with it? Do I have anything else to worry about like a bad low pressure pump? I changed the Donaldson filter as soon as I got home, so all three filters are new. I still have the old filters, any point in tearing them apart?

Thanks

[mlh]

Bad fuel filter? I think I would cut the fuel filter open just to see what’s in them. You did the best thing change filters. Low fuel pressure is bad news for these fuel systems. That is why Ford shut it down for you. Good you had filters with you. You can’t change em if you ain’t got em.
Lynwood

[scottz]

I forgot to mention, I use PM22 on almost every tank. I am real careful with the cap, foil & cardboard. Not to say I have not missed one, but I don't think so. The frame filter was tightened to the stop (had that problem on a different truck).

[scottz]

Update: The truck ran fine for about 900 miles. I didn't trust that the problem was resolved, so I took it on a trip over the holiday. Sure enough, on I-15 in Provo, Utah got "low fuel pressure" with loud whine from the low pressure pump followed by "reduced engine power" followed by sitting next to interstate (in rain & snow) with a dead truck; all this happened within about 90 seconds. I tried cranking it a couple times, no good. I called for a tow and we sat there for about an hour. When the tow still had not arrived, I cranked it again and it started. Made it the one mile to LHM Ford in Provo (good people). They diagnosed a bad low pressure pump, replaced it and got me back on the road the same day. The ESP paid for the pump less my $100 deductible. The only question is, what caused the pump to fail? The dealer suggested dropping the tank for inspection but that would have cost over $900 (twice the cost to replace the pump) and the truck would have been in for a couple more days, so I declined that offer. They ran all their tests on the fuel, looking for DEF, water, dirt, etc and found nothing. I've put another 500 miles on the truck, all is well. So, as long as there is nothing bad inside my tank, I think I'll be ok.