3.4 L Engine Loop

I have kind of the same problem. When I first start mine the runs varies from 1100 rpm to 500 to 800. Once the car warms up it seems to idle fine. Any help? I replaced all kinds of things including the ECM.
How do you know if the IAC is working properly? When I removed it and turned on the key the pintle retracted back. I was told it is working fine. Would love some input. Please respond.

It is normal for a fuel injected car to idle high when first started. It should last for about two minutes and idle down and stabilize at 750 rpm. The colder the weather the longer it takes to stabilize. To me, it looks like a normal car. If it idles irratic when first started, you may have a vacuum leak when cold and corrects itself when warm. You will have to check each and every vacuum hose, egr valve, intake for leaks. Good Luck.