Turbo cuts in and out?!?!?

[baja350]

I live down in Baja, and my 99.5 F350 (which has been running perfectly for 160,000) all of a sudden is having a power problem. At times the turbo works just fine and then it will just stop mid drive. Truck still runs, but w/o much power. Miles later and some worries, and it kicks back in??

Symptoms:
-Starts up just fine
-no turbo whine
-no turbo kick in power
-shifts gears later
-no smoke
-no fluids dripping
-no check engine lights

What I have done in the last 2 days:
changed oil and filter has 10W-40
changed air filter - was pretty fouled
changed fuel filter - was pretty fouled
drained the water out from the little thingy by the fuel filter

[Raul@Stealth Automotive]

take off your intake tube and check the turbo wheel.... make sure their is not excess play and grinding on the side of the housing..... also double check you dont have any boost leaks

[SCUFFY828]

sounds to me like the ebp valve is possibly shutting off when it isnt supposed to , a turbo will not work intermittent , if the engine is running it has to spinning the wheel unless its locked up, then it wouldnt work part of the time , unplug the ebp connector going to turbo and see if that makes a difference

[baja350]

WOW, thanks for the quick reply. I have to say here that I am novice mechanic and don't know were to look for a EBP valve is. As well, when I unplug it, does this mean that it should work or shouldn't work? by doing this can I do any damage? I am looking for a good diesel mechanic here but as you can imagine it is tough.

when the turbo works, it sounds like it did the day I bought it new.
there is a slight bit of oil on the 2 big top tubes (blue flexi connections), and dust like on every used turbo diesel, but I feel that is normal.

Are there good manuals online that can show me pictures of the engine?

again, thank you for your help
Cheers!