Well, I got the new pump in and it ran great for a couple of days, put about 200 miles on it with the new pump and the stumble was gone completely. Then this morning on the way to work it lost all power, will barely idle and left me stranded on the side of the road in the snow. I'm beginning to really dislike this truck.

I guess when it warms up a bit I'll grab the flatbed and the dodge and co recover the truck and see if I can figure out what's wrong this time or if the new pump just decided to die with 200 miles on it.

FML

 

My money is on a bad new pump.

 

Whatever happened to a constant duty cycle pump with regulator and return line. At least they were simple to diagnose, had pressure test ports and no control modules....

When I bought the pump I also bought a control module. Since the module is easy to change I'm going to swap it in and see if by chance it's the module, if not then it's happy happy, joy joy changing pump on a tank with about 25 gallons of gas in it.

Oh well, just grumpy because it's damn cold out. I did manage to get the truck home, went out and reset to computer then it ran enough to make it the 7 miles home so now it's at least in a warm shop waiting for me to calm down enough to go work on it...

 

did you change the fuel pump module also, if not it failed,
my truck has 1200 miles on it and is doing great.
David

 

I'll be changing that module as soon as I finish my lunch, just letting the truck warm up in the shop. I'll report back in a bit.

 

Still barely runs, inferred ethanol reading is up to 84.7% which should have reset, but didn't. Oh well, maybe I wasted money on a fuel pump and it was something else or maybe I wasted money on a fuel pump that went bad within two days. Eventually I'll get it running good...

 

Well I got the pump changed out with a new Motorcraft pump and control module and the truck is running great, let's see if it lasts more than two days this time...

 

Still running well?

 

So far it's running good and getting better mileage than before, but I've only put a couple hundred miles on it since replacing the pump again. The first replacement pump, the one that left me stranded then started working again, was a delphi and I had to chance driving it another hundred miles after it quit working (then started back...) and it was running poor and getting 6mpg. The new pump is a Motorcraft and so far I'm getting around 14-15mpg with a mix of highway, city, temps as low as -12F and driving in the snow, which increases rolling resistance of course.

I'm very happy with how it's been doing this week, but not quit confident enough to leave my coat and walking boots at home yet.

Thanks for checking in.

 

thanks for keeping us updated.

 

Has the fuel pump continued to keep this problem from arising? I have a 12’ with 173k and getting very similar symptoms. Hard start sometimes, sometimes dies when put in gear, stumble/hesitation from 1600-2000 rpm’s. Runs great when I get into it, not low on power. Just wanting to make sure it cured the problem before spending 600 bucks on the parts (pump and module). Man, parts prices have went up recently lol. Thanks anyways guys, I know it’s an old thread.

 

Have you checked Rock Auto? They are usually cheaper than most places and carry Motorcraft parts. Be sure and check the shipping if you order from them, sometimes it's a bit pricey.

 

https://parts.autonationfordwhitebea...gtZmxleA%3D%3D

 

Right on, thanks for sharing this! It helped me greatly in diagnosing my failing fuel pump. This 6.2 had about 138k miles but lots of idling as well. I also had flex fuel percentages in the eighties and the surging fuel pressure under light load. Both issues disappeared with a new motorcraft pump. I didn't replace the module. I think the older ones were more prone to failure.