I have a 2000 Blazer 2wd with the 4.3L V6 automatic.

I started it up the other day and turned the ac on and shifted it into reverse to leave, and just then the RPMs shoot up to about 1500 and powers the car without me giving it any gas. It has done it in drive as well. I'm have to turn my Blazer off, and then turn the ac off, then start the Blazer back up to get it to stop... and it only does it after i shift into gear so I need some help because I have no idea what could cause that, and the only guess I have left is that its the IACV.

I already looked at the throttle body and its clean and not sticking and my gas pedal is not sticking either. Looked for vacuum leaks and found none as well.

Any ideas anyone???