I have 2 things going on. The last couple of weeks it has been burning lots of gas, 7 MPG. Took 9 gallons to drive 64 miles. Not good
Truck has been cranking fine but no start at times the last couple weeks. Been hearing fuel pump work, but tonight I didnt hear it kick on and truck wouldnt start. Turned key again it came on.
Had service engine soon light come on yesterday, checked it, code po171 bank 1 too lean? I think fuel pump could be going out? But why the sudden increase in fuel useage? Thanks for any help!
BTW truck runs and idles great.

 

I have the same truck and my mpg's are terrible as well sometimes 5mpg sometimes 15mpg.
Having said that my issue has mainly been between ball joints, an alignment and poor U-joints.
Due to the problems I had with mine I would atleast check the u-joints on the front axles, my passenger side u-joint went last week and ruined my manual hub locking assembly, the wheel bearing, and I had to get a new axle from all of the pits and grooves due to the damage.(overall spent over $700 on parts alone, I did the work myself)

People think I'm crazy but I swear I can feel the alignment switch from good to bad and back in one trip. But Ford F250's are known for ball joint problems.

As far as the fuel pump I wouldn't know there.
My truck on occasion will turn over but not fire and/or start but quickly shut off. And yes my truck idles great too. This truck boggles my mind more than any other vehicle I've ever owned but I love her!

 

Could be a number of things. Gas cap, O2 sensor, injector issue, vacuum leak, etc. I had a vacuum leak in mine and did the same thing. It was a hose just to the left of the throttle-body. You can't see it unless you take the cover off, and then it's the one that has the 90 degree bend in it. Cost 30 bucks at the stealership and took about 5 minutes to change. I changed all other things I listed before I found this leak. Man was I pissed.

 

I had the same thing. Bad mileage and bank 1 lean. It was the same as huntinzombie.
The was a split in the pvc hose causing a vac leak. The dealer said there was a thin spot in the pcv hoses in 2000. Just run your fingers along the back side of the hose and you will feel the thin spot. Its very easy to replace.
Budman

 

Thanks alot for the help! Gonna check it out. Pump still not turning on all the time, Do you think it's bad a fuel pump also? Thanks gonna check out the hoses.

 

Oh btw, Somehow I got my old user name back when I had trouble logging in. I started this thread as jasonc . Thanks all

 

hummm seems these code's 171 are common, I also have this one along with a 174