Lately when I would try to start up my car it would start up then stall not 2 seconds after and it would do it about 3-5 times then it would run, but if I gave it a little gas it would start up no problem. Once it got running it would be fine and wouldn't stall again. I changed the IAC the other day so im pretty sure it isn't that. Please help, thank you

 

It sounds as if the IAC isn't allowing extra air into the plenum. That may not be the fault of the IAC, but the air passages need to be clear, and the ECM needs to control the IAC. If the IAC air passages were cleaned when the new IAC was installed, that should take resolve the first question. Is the IAC electrical connector intact?

What is the curb idle once the engine is at operating temperature? Does it maintain that RPM if load is applied (such as loading the engine with the steering pump or AC compressor)?