I've got a b16 with an idle problem, and everyone figures that my iac valve is f'd one way or another, but i honestly don't know where it is to check to see if it works, I know that it's on the intake manifold plenum, and i have a Haynes Service Manual that shows a tiny *** black and white pic of it, but call me stupid, I can't find the thing, its like a damn ****, haha. Anyone know an easy way to explain how to find it?

 

back of the intake manifold, near the throttle body. Correct me if im wrong

 

sorry to thread jack, but i have the smae question, and how can you tell if its bad?

 

Back of the intake manifold, secured by two 12mm bolts. Unplug the sensor and see if the engine idles at 450 RPM when fully hot, if it stalled, check your PCV system and make sure it is not clogged, and then adjust your base idle screw to 450 rpm and plug it back in.

If you idle is still low, or out of spec (spec is 670-750rpm full warm idle), the IACV could be clogged or stuck, remove it and clean the ports with brake cleaner. Easiest way to check for functionality is to unplug it and plug it back in several times, it should make a whoosh sound when you plug it back in.

 

slow civic, i have a question, my car after driven when i push the clutch in or shift into neutral the idle bounces from 1.5k to 1k then will go down to 750-800 rpm's.. but could the iac valve cause this?

 

You probably have a slight vacuum leak, which makes the IACV compensate for that extra air, by closing itself until the right idle speed is reached, if there is enough adjustment in the valve left for it to do so.

Does the idle speed slowly drop to 750rpm?