6.5 driving me nuts

[Brimmstone]

Okay folks this one has me pulling my hair out. I'm working on a 2000 H1 Hummer with the 6.5 diesel in it. The problem is when you get it up to about 50 mph and keep the throttle at a point to maintain that speed it starts cutting out. It will act like it has lost fuel then will run for a second and then act like it has lost fuel again. If you hit the pedal it will run fine. I'm going nuts because none of the scanners I have access to have any support for the hummer short of global OBDII. Any suggestions would be greatly appreciated

 

[chrisk1500]

Check the obvious - fuel filter clean? Lift pump working? Good fuel in it? SES light on? Fuel leaks anywhere?

 

[Brimmstone]

No codes in it. I've checked it with the shops Modis in generic, my Nemisis, and my Gensis. Only access I can get is through generic OBDII. I have almost no data through the scanner in datastream. It runs too good floored to be a filter or lift pump. It only acts up when you get it up to above 30 mph and try to cruise. The truck cuts in and out just like it has a dead spot in the pump. I don't normally work on 6.5s so i have no idea what I'm dealing with here with the PMD issues everyone is talking about. I'm almost dead positive its in the either the pump or the pedal position sensor. I have no info in ALLDATA about the truck. Do this sound like a PMD going bad and if so are there any tests I can do with a multimeter to either confirm or deny it is the cause. I have no wiring schematics to work with as no one has info on a hummer besides the dealers.

 

[chrisk1500]

So you actually checked out the LP and filter or you are just 'sure' that isn't the problem?