Had similar problem with my sr20. I took the iacv out and cleaned it with carb cleaner. When you have it out do a resistance check of the aac (the aac is on the iacv unit and is held on by 2 screws), should be 12 ohms. Next put a 12v power source to the solinoid (looks like a long 6 point bolt head on the iacv unit) and you will hear a clicking noise. If all checks out you have a good iacv. Finally do a continuity check of the iacv wiring. In my situation I had 2 open wires, one for the iacv (black with yellow stripe) and the other was a solid brown wire can't remember what it was for though. After the repair the car runs perfict! I ended up pulling the entire wiring harness out for continuity testing just to be sure. Don't let the harness intimidate you, it only takes about 15 min. to remove.
Another reasond I point out the iacv is because during the sr20 swap process, the wiring to that sensor is spliced in to a ka connector (the shop who did my swap forgot the 2 mentioned wires). Checkout
www.heavythrottle.com for info. There are diagrams for the wiring conversion, and there the best Iv'e seen.
Also do a continuity check of the maf harness since it's spliced/lengthened during the swap process. My harness clip to the maf used to be loose and my car would violently die too untill I secured it.