2003 GMC 2500HD 6.0 Idling Problem? Please help!
 

I have a GMC 2500HD w/ a 6.0 Motor w/ 130,000 miles on it. Resently the RPM's began to flutter while it idled. Being that I hadn't had a tune up yet I changed the spark plugs, Wires, fuel filter, and PCV Valve. Now it s running terrible. Shutting off a stop lights and even when pulling into the drive way if the Rev's get to low. I have been told it could be anything from the gapping in the plugs to the fuel pump! I was even told by someone that waiting so long for the tune up may have damaged the engine beyond repair? Any thoughs would be great! Thank You.

RE: 2003 GMC 2500HD 6.0 Idling Problem? Please help!
 

it runs fine on the highway?..just idles too low?..\

a couple things...gm has a software update for low idles on those years...a dealer must do it and cl;ean the throttle at the same time.
Of course,it could have a bad idle motor as well