In my 96 ex when the car is warm and operating the idle fluctuates between 1000 and 1500 rpm. This is really annoying at stop lights and I have done everything I can think of. First I found that my 2nd 02 sensor was bad (behind the cat) and replaced that. Then I took off the IAC and cleaned it out as best I could without taking it all the way out and soaking it in carb cleaner or something. I have also seafoamed the engine too see if that would help at. The only response I got was that cleaning the IAC helped a little the fluctuation doesn't occur as often but it still happeneds. What does anyone think is the trick to getting my idle back to 700 or so.

 

How about the FITV? Sorta like the AICV, but its mounted to the underside of the throttlebody, & its job is fast-idle when the engine is started cold.

Then maybe you have to go thru the whole process of adjusting your BASE idle.

 

tha fluctuacting has some to do with the computer trying to drop the idle but failing, i cant remember what the problem really is i was half a sleep in auto tech at school lol

 

Since the engine is warm, that takes the FITV out of the suspects. Since you cleaned the IACV and it still idle odd, the IAC sensor itself may need to be replaced. Before you go buying one, double check that you cleaned out both the upper and lower bypasses in the intake manifold (in front of the throttle butterfly) and the ports on the other side of the throttle butterfly.

 

Warm engine doesnt take the FITV out of the picture. The popular way for that to fail, is its internalsget loose, so it does NOT CLOSE when hot (like it should).

 

Thats true, Jim, sorry.

You can take the FITV off and heat the end of it with a lighter (dont put it in the direct flame) and see if it closes all the way, there was a DIY with pictures that I followed a few years ago when I had the same problem.