genopian

I have a 96 accord LX. It was just into a local mechanic for a tune-up. Asked him to look at engine idle because engine rpm drops to under 500 when a/c is turned on. He messed with the idle adjustment screw. What is happening now is when the vehicle is cool (start-up in the morning ) idle is great. After driving 35 minutes to work and the car is now warmed up the idle jumps up. Way up. if I were to put the car in park the idle rpm's would be almost 2000. I asked him to show me how to put the idle back to where it was and I have adjusted it back down but if I adjust it to much lower the car almost stalls when its cold. The idle is so high it is causing shift problems with the automatic trans when I try to stop. Any ideas from all you great thinkers? I really need some help.

Thanks

MCBlack_CB7

Maybe you have a vacuum leak, a clogged Idle Air Control Valve (IACV), or something with the Fast Idle Thermal valve (FIT valve). My honda was revving up and down so I messed with the idle adjustment screw and got it all right, but then it would be revving too high when it was all nice and warm. Cleaned and swapped out the IACV and the FIT valve, didn't work. Ended up having to take the intake off to put a new gasket on.


Theres all kinds of videos/threads for how to clean them.

IACV
https://honda-tech.com/forums/acura-integra-6/%2A%2A%2Ahow-clean%2A%2A%2A-your-iacv-k-idle-air-control-valve-1575913/

FIT valve on an Acura, but same design/concept.
https://honda-tech.com/forums/acura-integra-6/%2A%2A%2A-how-%2A%2A%2A-clean-your-fitv-aka-fast-idle-thermo-valve-1564019/


I found my vacuum leak by taking a cigarette, while the engine was off, then blowing the smoke in the intake thru a hose. The smoke came out of the area where the gasket was broken.

accordturb96

he hid one problem by creating another. The issue isnt the idle its something controlling the idle or not in this case. You cant fix a problem with another problem

95accordCE6

First check the IACV for proper operation as others suggested and clean if necessary. Once you're finished remove the fuse for the ecu for 10 seconds and then reinstall. Start the car with the iacv disconnected and adjust the idle screw to where the car is idling around 650rpm with no accessories (including cooling fans) running, if the fan comes on wait till it goes off to continue adjusting. Once you get it set remove the ecu fuse again and reinstall as well as the iac connector. While you're doing all this it can't hurt to double check tps voltage using a voltmeter, at closed throttle it should be between 0.48-0.50v and at wot between 4.48-4.80v roughly. Verify you don't have any vacuum leaks, although a leak would have been likely noticed prior to adjusting the throttle the first time. You can do this a variety of ways, easiest being to use carb cleaner slowly spraying all vacuum hoses, if a leak is present the idle will stumble a bit. If everything is working correctly you should have an idle between 750-850rpm without the ac on. Hope that helps