I have an 05 Dakota, AT, 4x4 4.7l with about 90K miles. Occasionally while stopped at a red light with the vehicle in drive, the engine wants to spudder and rattle, and watching the RPM it goes anywhere from down to 300 up to 1000. It's only happened 3 times now but this last time the truck lurched forward a tad until I slammed harder on the brake. It will also go away as soon as I start to accelerate and it doesn't happen while idling in park. Any ideas? Fuel filter? Dirty throttle body? Spark plugs?

 

My first thought would be to pull your throttle body and give your IAC valve a good cleaning.

 

I'm getting an induction cleaning which is scheduled for Thursday.

 

Hopefully you're not paying someone hundreds of dollars for that "induction cleaning". You can easily pull the tb off and clean it and the IAC in very short time.

 

Nope. Still under warranty from the car dealer. Hopefully that's all it is, since it happens pretty rarely I don't want to run out of warranty before it's fixed.

 

I've definitely seen the IAC valve cause these problems. It was amplified with the A/C on because of the additional engine load.