idle problem

1989 bII, idles high at about 1050rpms, then will jump to about 1200 than back down. I have cleaned TB, IAC, even put a meter on IAC getting 9.1 ohms. Could a small air leak in the IAC gasket cause this?

whats IAC

IAC= Idle Air Control
it is the small cylinder shaped item located on the intake manifold on the passenger side. It allows just enough air to bypass the throttle body plate to idle the engine.