Today after a all day heavy rain yesterday. I started up the Durango. When I step on the gas it stuck around 2000 rpm. Then the rpm dropped down bouncing between 600 too 1100 rpm. Until fully warmed up. It only did this very rarely. I was wondering if my TPS or IAC is starting to go bad?

 

Took out the IAC. It was all black and rusted. Gave it a good cleaning. Truck seems to idle fine after the cleaning.