A bad coolant sensor will give cold engine idle speed, yours is higher than that. Not likely the problem. If you can disconnect the IAV without a change in idle speed it means that the IAV is in the default wide open position and is either bad, or not receiving the proper electronic control. Easiest thing to do is swap in a known good IAV and see if it responnds differently. You have to make sure the throttle valve switch closes at idle, or it may always want to stay in decel mode, causing a high idle (though usually not as high as yours). The OVP and related circuits can cause problems. The ovp supplies current to the valve and the ecm provides a ground that varies in duty cycle to adjust the idle up or down. Gotta make sure all that works. A bad vacuum leak that has been adjusted for will also cause a high idle as well as an IAV connected backwards. Don't laugh, I've seen it