update: ford had my truck for 9 days and i just got it back friday with a new fuel tank. they say the problem was a malformation of the opening where the lines enter the top of the tank. apparently water has been able to pass through this which has accounted for my fuel issue for the last couple years. they also wanted to replace the fuel pump because it had junk in it. i asked them to clean the pump and reinstall since i has been running well, limp mode notwithstanding....and also because it would have been another $500. i have put 150 miles on it without incident so far so i sincerely hope this was the problem because it's damn near got me ready to trade it in. i've got over 90k miles so this was not covered under warranty but i'm going to make a case to ford that i've dealt with this since before my warranty expired (backed up by old service invoices) and the shop was unable to determine until now. think i will have any luck? this last service was $1000.

 

I have a 1999 7.3 and it has a switch by the fuel filter to drain the water.
I hardly ever get any water tho.

 

Thanks for the update on your truck problem....I would like to suggest ...Think real hard about trading your truck in . I owned a 2008 SD 6.4L at 117,000 miles my HPFP went out all by it self.....once at the dealership they stated that the HPFP was a poor design and it was bound to happen . The repairs cost me nothing because of my Diesel motor warranty....If your truck is no older than 4 years and has less than 100,000 miles maybe look at purchasing the Diesel motor warranty ...If so you can get coverage for 13 major engine componets which includes the HPFP.....good luck with your truck and keep us posted....

 

Since they never figured the cause till now what you have paid should go towards the actual repair...not the misdiagnosis.

I'd call them on that.