alright, I wasn't sure where to put this question but i decided to put it here. so lately when I've been driving on the highways and have my cruise set and its doesn't seem to be working properly. like when you drive up a slight incline your rpms will raise to keep a constant speed right? well I've been driving on level ground and my car will accelerate and then slow down, accelerate and then slow down, and so on. it creates a sorta jerky movement. anybody know what could be wrong?