ROUGH IDLE SOMETIMES
 

2003 DURAMAX 4X4 2500HD HAS RECENTLY STARTED IDLING ROUGH WITH LITTLE WHITE SMOKE AFTER ENGINE WARMED UP. CAN SHUT ENGINE OFF AND START BACK UP AND IDLES FINE THEN IN FEW MIN. STARTS IDLING ROUGH AGAIN. HAVE EDGE TUNER INSTALLED FOR TOWING. WHEM CHECKING INJECTOR BALANCE TUNER SHOWS THE BALANCE BUT WHEN IDLES ROUGH THE BALANCE OF ALL INJECTORS GO TO ZERO AND STAYS THAT WAY WHILE IDLING ROUGH BUT WHEN IDLES SMOOTH TUNER SHOW THE BALANCE OF ALL INJECTORS.

I would start with the Fuel dilevery system, it almost sounds like your describing a bad IP or low pressure to the IP .... my $.02:humm:

i would guess its the fuel pressure regulator.

can you check desired vs actual fuel pressure?

yes we checked all that. finally took it to shop and they checked it with scanner and # 2 injector was bad. Had left bank change and he had extra filter set up he installed for more protection. so far she running like a top. thanks for the advice.