My car seems to get a high idle after the car warms up or after I've driven it for a while. If I turn the car off and turn it back on it goes to normal idle for a little while then it jumps back up. I checked/cleaned the IACV and tested it (works fine), both hoses going to the IACV aren't cracked and are connected, microswitch was cleaned and lubed, throttle cable was cleaned and lubed. If its not vacuum or IACV what could it be that causes the car to idle only after it has warmed up??

__________________

1990 190E 3.0L