Originally Posted by Trash

I know you are dealing a lot with the IAC but I would suggest that is not the problem. Start the motor WITHOUT jumping into base timing. THEN jump A/B to get into base timing and THEN manually turn the distributor to get 8 deg BTDC. Remove jumper and see what happens. Idle will usually increase during base timing, that is normal. If it runs away after pulling the jumper you likely have a vacuum leak. Double triple dog dare check the TB blade is fully closed and throttle linkage allows it to close fully as well.