Ok when I start my car up it idles at about 2500 - 3000, after a few minutes it just starts revving from 1000 to 2500. It does this constantly, its gotten so bad I have to shut the car off at stoplights or engage the clutch enough for it to stay around 100o rpms. Any advice would be much appreciated. My car is my life and its killin me to have it do this. HELP ME PLEASE