High Idle

I just put a new head on my 2.7 1998 It starts and runs strong but it idling around 2000 rpms It trys to jump down to normal idle sometimes which lead me to belive it was the TPS but i put a new one on and no change. Theres no check engine light and I traced all the vacume lines and everything looks good, I even sprayed starting fluid all over while it was running and no change. Im just wondering if anyone has any ideas of what could be causing that. It has to be a sensor because it tryes to drop back down to normal idel and after you give it gas it tryes then also.

thanks