i have a stock b16 and when the car warms up and im not running the a/c the idle surges from 1000 to 1700 rpm but when i put the a/c on the idle returns to 800. i dont know what could be causing this. if its a sensor or a clogged valve. but i just wanna get ti fixed so that my car doesnt get hotter than it should before my road trip in a couple weeks

 

Any CEL codes?

Does your engine have an FITV or is it a stock B16a2?

 

stock b16a2, with a tuned p28

 

Tuned on what? CROME will do this if not tuned properly.

 

Check the resitance on the iac. Should be around 10 to 15 ohms.

How does the engine idle if you set the idle at 750rpms without ac running? Does it bog when you turn on the ac?

 

idk i bought it already tuned its got 2-step thats all i know, and it idles around 800rpms when cold with or without a/c but only when cold. and no it doesnt bog down when the a/c kicks in when the motor is cold. but when the motor is at running temp the a/c calms the surge

 

800 rpms seems pretty low for a cold engine warming up. I think the FITV put's it around 1250rpms or so. Check to see if your leaking any coolant from the feed or return hoses on the FITV.

If the idle surge is happening when your engine is warm, it's your IAC. Test it for resistance.

 

A stock B16a2 has no FITV.

 

alright thanks guys i do have a small hose leak thats getting fixed this weekend so ill check the iac along with it

 

good luk wit the fix