Exactly. If the raf (base running airflow is too high) un plugging the iac may help identify it. By unplugging the iac you freeze it in place. so when you rev the motor the ac wont open and allow even more airflow. if the idle settles back normal then thats the issue. If the raf is correct unplugging the iac and revving the car should cause it to die

 

Well, this at least belongs here in the EXTERNAL section.

I think you have the signs of a vacuum leak.

Check all the hoses and how well the manifold is bolted to the engine.

Also, make sure there's no leak between the MAF and the throttle body. Air sneaking in after the MAF is called "false air" and can make the PCM do wonky things.

 

I was able to get my idle hang to go away but now that it's cold (below 50) my car has trouble on start up. I have to give it some throttle for 15 sec or so...

 

well what did you do to get it to stop hanging? The problem is in the tune if its not a vacuum leak? Try getting propane and let it leak out near the intake, if the idle goes up theres a vac leak.

Now if you are absolutley positive there is no vacuum leak, then the tune needs work. There are tables for startup and base idle airflow that control all of this. Getting the throttle set correctly is paramount to make sure these tables are correct.

Without a tune file from the car we cant really do anything. The best advice I can give you now is to make sure you have no vac leaks and then get the car hot and unplug the iac. You want it so that the car will barely stay running with the iac unplugged adjust you tb set screw until this happens. Once there plug in the iac and see how it is. If you still have issues then the tune needs work