Idle RPM seems to fluctuate but most of the time is over 1000 RPM (usually up around 1500 RPM). It can and does range anywhere from 1700 RPM to a low of say 300 RPM but as I say the majority of the time over 1000. Doesnt seem to be any rhyme or reason to it. One shop told me it could be the throttle body sensor (did he mean throttle position sensor?) And /or the throttle body itself. Another shop said this was wrong; the only thing a defective throttle position sensor will do is cause your car to stall! And what does the idle air control valve do? Could this be the problem? Someone else said something about vacuum lines. Any help appreciated. Thanks very much.