Hey guys im new on here to and i have a 2001 GMC and it has been doing the same thing and i have changed the fuel filter and had codes read and sometimes it says there is a large leak in the fuel system and last time it said bad ECM and i changed that and it still does it i have had it at 2 or 3 shops and at the dealership 7 times and no one can figure it out . it is about to drive me crazy and i am ready to get rid of the truck but i have so much money tied up in it now that it would be hard .i have had to put a new trans in it at 265000miles and had the brakes rebuilt so you see how much money i have tied up in it. i have a 2007 chezy 2500 and it is awsome i have never been in a diesel truck with as much power as what these trucks have so all the help you can give would be greatly appreciated