1995 4Runner V6, auto trans.,4X4 - when idleing the motor will speed up to say 1200 RPM then drop to 7-800 RPM and run rough, then possibly speed up again, and so on. Can't keep the idle steady. It has new plugs and I haven't found a broken air line. Could there be problems with the idle control motor? Any info on where to start looking is appreciated.