I had a loopy idle so I cleaned my IACV and now the loopy idle is gone but its idling at 600 or so rpms. I turned the screw on the TB and that did nothing.

 

unplug the iac and set the base idle the right way with the screw on the TB. Shut the car off and plug the iac back in and reset the ecu by pulling the back up fuse or disconnecting the negative on the battery.

The main cause of a looping idle is a vacuum leak causing high idle.If the ecu sees the rpm above 1100 rpm and the throttle is closed(tps sensor at less than .5v) it shuts the injectors off. When that happens the idle drops back below 1100 and the injectors come back on, causing the up and down idle. The ecu is programmed to do this because it shuts off the injectors on deceleration to save fuel which is what it thinks is happening. Main causes of a vacuum leak can include a bad vacuum hose on a firewall mounted map sensor, timing off a tooth or more, intake mani gasket, or a dead fast idle valve that isnt closing completely once the car is warmed up and letting extra air in the manifold.

 

I just did that, the idle screw had no effect on the idle.