I have a 2002 1500 Ram 4.7 that goes wide open when cranking. The throttle does not move nor does the throttle butterfly. I've tried disconnecting the IAC and TPS with no difference. This started the other day and I cranked the truck and it backfired. Everything looks ok under the hood, no hoses loose etc. I found another person that has the same problem only it's on her Neon so not sure if trouble will be the same.

 

Is this a new vehicle to you? When did it last run? What happened to make it stop?

 

I've had it a few years with no troubles before this. I went to crank it the other day and it backfired real load. That is when the trouble started.

 

Pull the valve covers to make sure all the rockers move when the engine is turning over. Also, because the intake is plastic, they have been known to crack when a large backfire happens

 

The engine cranks, it just revs all the way up. Like I have the gas pedal to the floor. I check the intake with a light and couldn't see any cracks or holes.

 

Yeah, sounds exactly like a vacuum leak or cracked intake

 

I'll recheck the engine for leaks/cracks this evening when it get dark. Be able to see problems better then. Thanks

 

Sounds like a bad IAC valve

 

I disconnected the IAC connector and it did the same thing. Could it have still been bad? Thanks

 

Yes, Id find out what the test procedures are for that sensor and take a meter to it.