I have a 2001 5.9 Ram with about 66K on it. Recently, the cold idle is going crazy all by itself. It will rev all the way up to 2500 rpms and back down, over and over. Sounds like there is someone in there pumping the accelerator. Keeps doing it until the truck is up to operating temp. I replaced the IAC last spring. Any ideas where to start?

 

Did you do the FIPK NO MORE mod? Mine does the same thing because of it...

 

Nope, pretty much all stock.

 

did it just start doing this ? sounds like last years IAC has failed...

 

Yeah, that's kind of what I'm thinking too. IAC is a pretty cheap fix so I guess I'll start there. I used one from NAPA last time, maybe I'll spring for the OEM one this time.