Did you try resetting the base Idle? Too do this you must
1} know how to get you car in field service mode
(short pins A and B) In the ALDL this will seat the IAC in 45 secs.
2} After 45 Secs unplug the Iac and the Timing spoct connector
3} Start enigine and note Idle RPM's (my guess right here is that you wont even start at all)
4} adjust you throttle stop screw till you get 550 RPMs ( you may need to turn this up till you can get the car to Idle) then turn done as necceary
5} turn car off then replug everything back in.
6} depress gas slightly then start car and leave it high Idle for 5 secs
7} Shut car off then let sit for min 10 secs
8} restart car and let ldle return to its normal setting.
The car may not come down to it previous Idle but after a few trips it will relearn as nessary | 
