I after switching to an auto tranny and the weather cooling down I had to bump up my idle. I did it and it idled at about 800 and it was nice, the next day when I drove to school and the motor fully warmed up. I put my truck in park and the idle went up to 1200. I got out and poped the hood. I made sure the throttle linkage was pulled all the way closed and it still idled at 1200. So I had to turn it down. Now the truck idles at when I first start it at 250 and when it warms up about 500. I need to turn it back up. But I can't have it hanging up at 1200 when I throw it in park