Hey I just traded for another cummins and this one is a little sick! I have read a post with the exact problem but no one ever posted what was found to be the problem! OK here it is... 05 club cab 150000 auto. When you start it and let it ladle for a min it will start to almost lope a little. And when you give it pedal it will hold the rpm for about 10 sec. When you get to around 2200 rpm it will just keep on holding the 2200 and so forth. It is a rougher idle and if I match the idle with the the pedal it will smooth out a little. And the only way to get it to idle is to turn the key off and restart! And while you are driving it will hold speed and has a little surge back and forth. Fuel filter has been changed per my buddy who said he was sick of dodge and cummins! So I am swapping him my 02 7.3. . I just hope I am doing the right thing! Lol any help for a fix would be greatly appreciated! ! It is my duck hunting truck and season is not over! And I am not going to gravel and mud my dually up! Lol thanks

 

Have you turned your key on and off 3 times to see if
there is any codes ?

 

Sounds like injectors hanging open and just dumping fuel. I would get it on a scanner so you can watch each injector fire and such to see if everything is functioning right