Idle speed control valve? That one is new to me.. Are you talking about the Throttle position sensor? That only regulates how open the ECU thinks the throttle is, which would only result in high idle, not bouncing idle. Either way, my TPS is set correctly. I cleaned the IACV with throttle body cleaner yesterday, and the FITV is pushed back as far as it will go (now the little ring cap/plunger is cracked), and still it is high as ever but lower when I cover the hole.