Having problem and can't find out whats wrong. Car starts fine but then after driving for about 20 mins it goes up to that rpm and won't come down till i shut it down and the motor cools down. Like around 1500 to 1800 rpm. I drive a 1990 2dr sentra auto 1.6. Please help, no one can find out whats going on. I looked at the sticky throttle post, sounds like it might work but why does it not do it all the time. Seems like i have the only car that every did this cause no one can seem to find out what the hell is going on. Replaced O2, computer under seat, and had 3 or 4 other mechs look at it, can't put any more money into it because my wife is going crazy that i am spending 2x what the car cost to not fix it and get it right. Tranny went last week and he told me to get the idle fixed or its a rebuilt next time(ouch) wife will flip if that happens, so please can some one figure this out for me and save my ass.