So, I just had the fuel pump replaced on my '15 6.7 a month ago and it just died again. (next day edit: it didn't actually die, it showed all the same symptoms)
Same symptoms: whining sound, low fuel pressure warning, reduced power warning.
This time I'm 50 miles from home so I pulled off the road before it shut off. Interesting, I was in a hilly area and my low fuel warning came on too.
We are waiting for a tow.
I was considering trying to push on but don't want to get stuck in a dangerous spot on the highway. We're in a church parking lot.


Edit: So, last time this happened I was on flat road with about a half tank of fuel on a lunch break. I ran a mile after the warnings came on to feel out the issue and to see what would happen. I happened to be only about a mile away from my dealer so I drove that way. I got reduced power warning and then it cut power on me (limp mode). I made it to about 100 yards away before it cut off.

This time, I was in a hilly area at night on a windy two lane road with no shoulders in the woods. I was miles from civilization and was showing below a quarter tank of fuel. ~100 miles to EMPTY.
I got the low fuel pressure warning first and then the reduced power mode before the whining noise started. I was climbing a hill on a curve at the time. I drove a quarter mile and then pulled off the road into a parking lot so I wouldn't be stuck on the shoulder. It didn't actually go into limp mode.

I let it sit a few minutes, talked it over with the wife and decided to call for a tow. After talking to the tow truck driver who said he would be an hour because he had to go find a bigger truck, I decided to see what I could do while I wait. I fired it back up and the fuel level dropped to below 1/8 and I was now showing 33 miles to EMPTY. WTF!? I was parked on a hill with the back end up. I had backed the truck into a space to make it easier for the tow truck driver. I let it run a minute, checked for leaks and it seemed to run fine with no studdering or additional warning lights. CEL was on but no new warnings. I put in my code reader and pulled the P0087. Just one code. I revved it a bit to see if there were any issues. It seemed fine so I decided to try my luck. I started driving towards home with the intention to stop at the first diesel station to fill up. Truck ran fine. After two minutes of driving gently, heart racing, my fuel level came back up and it now read 88 miles to EMPTY. I drove 11 miles to the nearest station and filled up. No issues. I shut it down. I fired it back up. Still no issues so with a full tank, I drove home the remaining 30 miles without issue.

Planning to take it in to the dealer Monday to get it checked. Could this be from an air pocked due to low fuel level and hilly terrain? Is my new pump dying already? Is there something else going on inside the tank or elsewhere? Any other ideas?

I asked moderators to move this to the 6.7L forum. I think that's a better spot.

 

Code is P0087, low fuel pressure.

 

When I had my 2015, it did that to me 3 times, the third time it happened, I hauled it back to the dealer I bought it from and told I wanted to know WHY this is happening! They tore into it, and after 2 days of digging and poking, said high pressure fuel system was starting to fail. They took about 40 fuel samples, found all fuel was good and warrantied it. But, after this many times, I did not feel like I wanted to try to gain trust in that truck again, so traded for an identical 2016 that he had on his lot....without taking TOO much of a bath on the deal! I DID put 20,000 miles on the '15, so it was not like it was "brand new"!!! Now, the '16 has been flawless. So I dont know if that was the underlying cause, or not! Hopefully, yours is just a flawed low pressure pump
There was a fiat dealer right next to the Ford dealer there, and gave STRONG consideration of their product, but they did not have a truck on their lot that was equipped the way I wanted it, and I did not like the idea that fiat wants $3000 extra to get a transmission equal to what Ford ot GM offers as standard equipment!

 

Thanks for the feedback. I wonder if my issue was actually the high pressure pump not the low pressure pump?

 

I dont know, but I would definitely be telling the dealer that I want to know WHY is my low pressure pump failing!
And since I traded my '15, I dont know if the HPFP rectified the situation or not.......it was then their headache, which I am sure they put a new HPFP system in and sold it as soon as thet could. Hopefully, the next buyer has no trouble with it.
I tried to lemon law it, but the state I bought it in will only lemon up to 10,000 GVW, and being a dually, that left me out!
Best of luck to you getting it straightened out!

 

Very interesting.

Moving this one to the 6.7L forum. The fuel pump is in the DFCM, and it almost sounds like something wrong with the sending unit in the tank.

 

I am now on my 3rd pump. The original lasted 35,662 miles. The next pump went at 36,741 miles. The first time it went I ordered two pumps one from my dealer, they had one in stock and another from Amazon which was way cheaper. Dealer was 328 and Amazon was 238. I am glad I ordered the extra one. Its really easy to change them, you really could do it on the side of the road. You will need a 3/8 ratchet with a 1/2 deep well socket and a 1/4 drive ratchet with a 7mm socket. And the new pump and new fuel filters. The new pump comes with a new filter but Ford still recommends replacing the filter on the engine too which I agree with. I also have a blanket to lay on and contractor trash bag for fuel spillage. I can do this job in an hour. I got another spare pump from Amazon and filters from diesel filters online. I carry these things in the truck at all times. I think it almost takes as long to prime the system and get rid of all the air as it does to change the pump.
A bad pump has an unmistakable sound, the last time it went I heard the sound even before the light came on.
I think the next time it goes this truck will be gone and I will go back to gas.

 

Do you use any additives with the fuel, more specifically Ford/Motorcraft's PM-22/PM-23?

 

I do, every tank. I buy it by the case at my local dealer.

 

Wondering of the pick up tube in the tank is becoming blocked on occasion, like from a a paper lid for pm 22. That little piece of paper that comes out of the lid.

 

That's EXACTLY where I was going.

Diesel Technician Society

 

I do use the Motorcraft additive but I'm good about not losing that little seal. I can't say for sure, that I've never dropped one in the tank but I am careful.
I took it out for a short test drive this AM with no issues. CEL stayed on the whole time. No new codes, just the one.
I took it out again tonight. CEL went out as soon as I fired it up. We made two stops over three hours, three total start-stop cycles. No issues.

Anyone else ever get a low pressure warning from driving around curves?

Planning to call and schedule an appt first thing Monday.

 

I have heard about this a few years ago. Before I put the bottle in the truck, I cut off the foil and take out the cardboard cap, so I know nothing gets dropped in the tank.

 

It's one of the wonders of life. That cap seems to be the perfect size to almost completely block off the opening of the fuel pickup inside the tank. Once you shut the engine off (and the fuel pump stops working), that piece will fall back off somewhere inside the tank. Upon the next startup, life will be good, and back to normal with that piece floating around somewhere inside the tank, just until it gets sucked up against the opening of the pickup again and we're into this all over again. That is, until the tank is dropped and the fuel sender and pickup assembly is removed for an inspection. This has fooled many a dealer technician, so I try to share this to help as many out there as possible.

 

That sucks Mystic Cobra... I hope they get it figured out.