Sounds suspiciously like an IAC. Have you ever cleaned the throttle plate and not covered the holes to it? If not, then the coils may be fried. Not cheap, but easy to fix.

EDIT: Maybe somebody will chime in with the test procedure for it. Or, follow MontyMcV's sig to the FSM's <img src="/forums/images/graemlins/kewl.gif" alt="" />

Last edited by hazy_daze; 05/14/08 10:04 PM.
Fasteddy's advice is occasionally sound...