Ford Truck Enthusiasts Forums - Low Fuel Pressure

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Low Fuel Pressure

I know this have been beat to death, 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

As answered on another forum...

Do you use fuel additives? By chance, have you dropped one of the bottle seals into the tank? That is a known problem and does happen at times, not often but there are reports of it on the various forums.

I doubt tearing or cutting the filters apart is going to show anything of value. Did you save the o-ring? Have you check it for a slight nick? Are you sure the DFCM cup was tightened to the stops?

Thanks Larrry; same answer I gave on other forum :) (can't get too many opinions). 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. I still have the o-ring; I'll take a look at it.

Did you resolve your low fuel pressure DTCs yet? About to diagnose a similar symptom.

No answers. The problem has not come back since I changed the filters sitting next to the interstate. The truck is running fine so far.

It just could be that the top filter was compromised.

Lower filter you can see and tell.

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.

I've had the exact same issue occur 2x. The first last January left me in limp mode and I pulled off into a Home Depot parking lot planning to call for a tow. I spend 20 min in HD and when I came out it started up, no limp mode but the CEL was still on. It ran fine and I drove it 20 miles to the Ford dealer. I was told it was "LIKELY" the fuel filters ( they had about 7k on them) and I change them every 15k. They kept it for 4 days changed the filters and charged me $500 and gave it back. All was good until it wasn't and it happened again in April. I was traveling with my trailer in tow. It was in limp mode again and I pulled over and waited 15 minutes. It started up, no limp mode and I drove on hoping to get to my campground. It happened 2x more starting up and going 5 miles or so until I finally made it to the CG. I unhooked my trailer and let it sit a few hours before heading out to a nearby Ford dealer to purchase a set of filters. It ran fine, no limp mode and eventually after a week or so the CEL cleared on its own. I never have installed the filters I purchased yet and am coming due any time now but it's run normal since then and it was back to Ford just last week for the cold air tube blowing off and this never came up when they hooked it to the computers.

I think these trucks are super sensitive to electronic anomolies and will throw codes quickly and then clear them when they don't re-occur. There's no doubt in my mind that there is some quirk in the low pressure system but unless their mechanic is good enough and persistant enough to track it down they just will let it go until it fails and then replace it. I do use the additives sometimes but I'm super careful with the foil cap so I know that's not my issue. So all's well until it happens again.

Quote:

Originally Posted by polarlys (Post 18340652)

I think these trucks are super sensitive to electronic anomolies and will throw codes quickly and then clear them when they don't re-occur. There's no doubt in my mind that there is some quirk in the low pressure system but unless their mechanic is good enough and persistant enough to track it down they just will let it go until it fails and then replace it..

BINGO..............for the WIN!!!!!!!!!!!!! I think you are 100% spot on here. WhenI bought my ‘15, it started quirky little things within seconds of the first time it went into regen! I had it in to a couple different Ford dealers to try toi diagnose what was happening.......nothing without an active code! I then took it to a dealer near where I was living, explained the situation, and left it with them for a few days. They told me they found a couple of “Latent codes” (whatever that meant), cleared them, and all was OK. A few months later, while on a road trip, “LOW FUEL PRESSURE’ light came on, about 4-500 miles after replacing fuel filters. Hauled it to a Ford dealer nearby, changed out filters again, all pressures showed normal. (I rode with the service tech while he had his laptop connected) while driving in some hills so we could load the engine. All went well for a few more months, then about 1/4 mile from my house “LOW FUEL PRESSURE” light AGAIN!! So hauled it to my local dealer again. They said the low pressure pump was bad, replaced it, and all was well again. Fast forward another 3 months. I was on the road, pulling a 38’ enclosed gooseneck, loaded....”LOW FUEL PRESSURE”........yup!!! All this in about 13 months of ownership! I parked the trailer where it was secure, loaded the truck and hauled it back to the dealer where I bought the truck, and told them I wanted to KNOW exactly what was causing this!! Well, after about 3 days of diagnostics, they came back and said the whole fuel system needed replacing. I asked them what CAUSED the failure. They did not know. AND the fuel system for the ‘15 was on national back order!! Well, at this time, I no loger trusted the truck, and took all this information in to the manager of the dealership and asked him just what the hell they were going to do to fix it.......and then leveraged a damn good trade for the ‘16 I now own. (The state I purchased the ‘15 in only lemon lawed up to 10,000 GVW, and mine being a 350 dually was out)

So, with all this being said, I believe all this was the result of some minor electronic glitch that none of the techs seemed to want to try to find. I have my doubts if replacing the fuel system fixed the vehicle.

Just wondering how cold was it when it happened?

Quote:

Originally Posted by gsxr1300 (Post 18342156)

Just wondering how cold was it when it happened?

for me it was various times of the year........never in COLD weather. Purchsed it in early Oct in Montana, First LFP light, summer in the Black Hills of SD, second LFP, early fall in AZ, 3rd, mid OCT in ND, never once when ity was even below freezing. Others, I can’t tell you.

In my case the first time was January so it was cold. Truck engine was warmed up. Second time was April so weather was mild but it happened first thing on the road so truck was not yet warmed up. So no consistency in my cases. When I'm home I usually get fuel at a high volume supplier. When on the road I can't be too picky. I do use the Ford additive but only sometimes.