02 E-350 stalling at 50mph and while going uphill

[jordison460]

Any help with this would be GREATLY appreciated!! What do you think this could be (van is broke down at local gas station)

2002 E-350 7.3 WITH 260,000 MILES--
**Acts like its running out of fuel at 50-60mph AND whenever going uphill
**Will blow a little blue and white smoke
**Idle is fine
**NO check engine light
**when it starts to stall the idle is all over the place, but if I turn it off then turn it back on it will fire right up
**Usually enjoys doing it after 10 mins of driving
**Turbo wont go over 4psi of boost at full throttle doing 0-50mph...then it acts like it running out of fuel

WHAT IT HAVE DONE SO FAR-
**Replaced CPS
**Dropped fuel tank cleaned and drained inside, and refueled with 20 gallons
**Changed fuel filter
**Oil is good
**Replaced fuel pump
**Replaced air filter

...Same result after all that.

Here was my mental process..I first figured if it was affected by driving uphill then it must be related to oil or fuel shifting to the back of the tank. I thought somehow there was air in the fuel line, but then I remembered the air is recirculated throughout the tank...or so I read. The old fuel pump buzzed LOUDLY for about 45 seconds, I put a new one on it and it still buzzed very loud for 45 seconds. Funny thing is that I took his old fuel pump and tested it on my 03 F-250 and it did not buzz nowhere near as loud or as long..so fuel pumps only seem to buzz VERY LOUD and VERY LONG on his van.

I know its a lot, but any help would be appreciated!!

Thanks all

[jordison460]

I feel like this is a frankenstein problem....It doesnt seem to match any problem I have found between doing internet research but it seems like it has 5-6 problems rolled in one..anyone want to take a stab at it? thanks all!