P0191 - weird breakdown yesterday - Fuel System Issue??

[ScrapIron]

Exact same thing my Chinook V-10 did a couple years back. It would run great sitting idle or driving on flat ground, as soon as i pulled a hill it would struggle, cut out, and struggle. It threw the exact same codes... ended up being the fuel pump. I had the Ford dealer do the work and i had them replace the fuel pump and the fuel pump driver which is mounted on the frame rail. They snapped the studs out of the gas tank because the kid used an impact gun on the small fuel pump bolts so i ened up having to buy a brand new gas tank as well... but thats a story for another day.

[ridgerunner]

Thank you for the quick replies. I'm off to the dealership now armed with a bit more info.

[Mr.Anderson]

Interestingly, from my OP last summer on this, I actually never replaced the fuel pump although it sounds like that is the most likely culprit of this stall out issue. I spoke with a couple mechanics and they both said the fuel pump either works or it doesn't so I replaced the fuel filter, drove another 5,000 miles that summer (2021) had the issue come up once more while driving up a long hill after which I cleared the code and kept on going. Since then (Oct 2021) I've put another 30,000 miles on the van and have not had the issue happen again. I did replace the fuel filter once more last spring after 10,000 miles on it but that's it.



Not really conclusive evidence but more data for this problem. Based on what people here are saying if it's a frequent issue (occurring every few hundred miles) I'd definitely get a new fuel pump installed. The fuel pump driver is also an easy swap so maybe replace that or at least inspect it before doing the full fuel pump, the electrical connections on the driver can get damaged and corroded.



@ScrapIron - that's some BS about having to pay for a new tank when the dealer, damaged it - my condolences.

[ridgerunner]

Originally Posted by Mr.Anderson

... I actually never replaced the fuel pump ...

This is helpful info. I'm back from the dealership; their main tech assigned to this was out sick today.


As a retired engineer having worked on the closely knit interactions of hardware & firmware my entire career, (I worked the firmware end), I'm well aware of how a computer can get confused from the many inputs it has to deal with. 99% of the time, the van runs it runs great with loads of power. I find it difficult to believe that a fuel pump can go out with only 47K miles of very easy driving.


I miss the days of simple gravity fed carburetors needing no electronics whatsoever. (But then again, I'm an old curmudeon!)


I'll post any updates on this issue. Thanks again for the feedback

[N147JK]

Originally Posted by ridgerunner

I miss the days of simple gravity fed carburetors needing no electronics whatsoever.)

I still operate a vehicle with one - they have their own problems and plenty of ways to fail. We tend to just trade one set of problems for a different set.

[deserteagle56]

Originally Posted by N147JK

I still operate a vehicle with one - they have their own problems and plenty of ways to fail. We tend to just trade one set of problems for a different set.

Exactly. I remember replacing the problematic Rochester on my small-block 400 with a fancy (and expensive) Holley that was supposedly trouble free. It did work better than the Rochester but I still had to rebuild it several times in the time I owned that rig.

[Mr.Anderson]

Following up again on this thread - the fuel pump finally died!

I had the first breakdown from the P0191 code (low fuel rail pressure sensor) back in August of 2021. I've put down around 25 - 30k miles on it since then and this last June (2023) I had a breakdown while towing a trailer, the engine would stall out while at stop lights or stop signs and studder and be underpowered while moving. I'm lucky I was close to home and was able to limp the van to my house then had towed it to a ford dealer. They replace the fuel pump, they also replaced the fuel pressure rail sensor on their recommendation so could it have been a faulty sensor, maybe but probably not (it was doing it's job and sensing the fuel rail pressure being low).

Van has been running fine since.

Just to close the loop on this since it's a common issue with these Fords. I guess if you have intermittent P0191 codes replace the fuel pump, because it will probably die within 12 to 24 months anyway and you don't want to be 200 miles into the badlands when that happens.