I have a 2003 F450 with the almighty V10 . Truck as roughly 200K and has been great until this little problem. Running down the road last week truck became real dogie, loss of power, spit sputter the whole deal. If I shut the truck off then immediately re-start everything is OK for 5-6 miles. Brought it into the shop and checked fuel pressure... 28 lbs. OK but not great. Change fuel filter, rechecked fuel pressure, 34 lbs. Test drive, 5 miles later symptoms returns. Back in the shop and drop the tank. Pull the pump and replace it ( both filter socks really dirty). Road test 10 miles all is good. Next day I get about 20 miles from home and it acts up again limp home and back into the shop. Check fuel pressure again... 34-35 lbs. Decide to leave fuel pressure gauge hooked up and road test. When the truck acts up fuel pressure drops to 4-5 lbs (amazed it will run ) Shut truck off, immediately re-start back to 34-35 lbs. Back to the shop.... Now I hook up a vantage multi-meter so I can moniter fuel pressure, voltage and amperage draw. Road test.... Before the truck acts up, I am getting 38-41 lbs fuel pressure, 13.7 vdc and the pump draws 3-4 amps. When the truck acts up, I get 4-5 lbs fuel pressure, 13.7vdc and the pump only draws .3 (point 3) amps. Shut the truck off, immediately re-start and back to where I started.

Anyone run into anything like this? Only other thing I can think of is a resistance problem with the wiring inside the tank or a bad replacement pump. The one thing I can't understand is why when I shut the truck off and immediately restart all is good for 5-6 miles

HELP!!!

P.S. No codes, no CEL.

 

Is the 13.7 vdc just somewhere generically in the engine compartment, or is it right at the pump?

 

Isn't there a fuel regulator between the fuel pump and the cylinders? If so, maybe you have a restricted flow into the regulator, but the regulator is able to maintain the higher pressure for a few miles....

 

And actually, what tells the fuel pump to pump? And where is it grounded? Is the fuel pump controlled by interrupting or adjusting the ground?

 

Did you change the fuel pump relay yet?

 

REV_MAN: I have a neighbor who has a V-10 and is currently having what appears to be exactly the same problem. While I was picking up my 6.0 from being repaired tonight I showed him your post, and asked if he had any clues. He said that since you had replaced the fuel pump, and found the socks to be really dirty, which is a bit abnormal, that what you probably have is the coating on the inside of your tank delaminating and getting sucked into the sock, blocking the fuel flow. He suggested that you drop your tank and clean it out. He said that he has seen this happen to f-450's on several occasions. Good luck.

 

REV_Man
Did you get any where with this? I have a 2005 doing the same thing. Would love to know how you fixed it.

Thanks
Tim

 

Since I started this topic a year ago, the truck "fixed" itself, not 100% but drivable for the last 11 months. Well today it started acting up real bad again. Went back through everything as I stated in my original post with the exception of the fuel pump, that is tomorrows project.

Has anyone seen another like it?

Tim I never did find the cause, you have any luck with your 05 ?

 

I was just wandering did you ever replace the fuel pump relay like Krewat suggested?

 

Everyone I spoke too said there is no fuel pump relay. I thought that was strange. Anyone know where it is located?

 

Rev-man,

Haynes Ford book says ,it is located in the fuse box (based on the photo for 2001 models- at lower right corner in the fuse box ). And it also says"The fuel pump relay is equipped with a primary and secondary voltage circuit . The primary circuit is controlled by the PCM and the secondary circuit is linked directly to battery voltage from the ignition switch ".

If I were you I would do what krewat says . Good luck.
Ken

 

You either have a bad connection or you are sucking air. When you suck air the pump has not load in it and won't draw as much current.

Perry

 

The relay is located in the central juction box which is under the dash on the drivers side.

 

Well I worked most of the night on the truck outside in the driveway @ 15*.I feel like a Popsicle Didn't make any progress. Unable to locate the fuel pump relay. Going to try a fuel pressure regulator and if no change, try another pump.

 

Update: Truck seems to be fixed. Combination of bad fuel pump and bad fuel pressure regulator.