I have a 2001 dodge ram 2500 5.9 that does the same thing! In the morning I start it up and after idling for a min. Or two it starts to idle rough. If I try to drive it it looses power and backfires and will dye if I stay on the gas but if I let off the gas it continues to idle rough. I found if I shift into nuetral and rev it up it clears up usualy or if I shut the engine off and restart it it clears up. When its doing this I can hear a hissing sound coming from the throttle body. I thought it was the IAC motor but I replaced it and it still does it. Ive changed plugs, wires, cap, rotar, intake gasket, cleaned throttle body. There are NO engine codes! This problem always happens right after starting the truck after its ben sitting and the engine has cooled off. When the problem occurs now I just shut the truck off and restart it and it goes away instantly. I'm very mechanicaly inclined and have tools and garage to fix anythig as I used to race cars and have done just about everything from building engines to changing tires. Ive worked on everything from FreightLiners to snowmobiles and lawnmowers. I currently work at a John Deere dealership and I cant for the life of me figure out what the hell is causing this! I do have a few more things to try though and I will let u know when I figure it out!
Thursday, February 16th, 2012 AT 8:58 PM