Hi, I just bought a 1992 Accord 2.2l. It will not pass CA smog due to high idle @ 1000 in Neutral...all loads off.
So far I have checked timing at 15 degrees BTDC, replaced the IAC due to the screen being mutilated, checked codes..none, and attempted to lower the idle with the air adjust screw at the throttle body. It looks like someone has been chasing this problem before me, as everything I look at has been "touched" in a not so gentle way.
I also tracked all vacuum lines and sprayed chem-tool in search of vacuum leaks. And I have opened the top of the fast idle thermal valve while at idle....no change in idle speed just an audible change in vacuum. The plastic screw/seat is tightened the whole way down.

Can anyone shed some more light on this?? Oh-yeah- the previous owner recently replaced the timing belt (he says). Any experience with cam timing and idle speed?

Thanks for your help......

 

If the timing is 15 BTC, then the timing belt is installed properly.

Does the check engine light turn on for two seconds when you first turn the key to the II position? Does the CEL turn on or the D4 (or S) light start flashing when driving? Check for error codes anyway. See how to get CEL codes in the DIY section. Post any codes you find.

I would clean the throttle body and both sides of the throttle plate with throttle body cleaner. Is there some slack on the throttle cable?

You may also want to read this thread about fluctuating idle. https://www.hondaaccordforum.com/for...ad.php?t=35704

Maybe reset the ECU after checking for error code(s) by pulling the 7.5 amp backup/radio fuse in the engine bay fuse box for a minute.

 

Thanks PAhonda. I have cleaned the throttle body, cleared the PCM by disconnecting the battery for 1 minute. Rechecked codes and found none. Still idles at 1000 rpm. Runs fine just wont idle down. Frustrated.
I even thought maybe the fast idle thermal valve was leaking air. So I blocked off both holes and it still idles high. At least I eliminated the valve.

 

I think that you need to set the base idle. Read JimBlake's instructions on this thread.

https://www.hondaaccordforum.com/for...ad.php?t=30759

 

That thread is kinda scattered. Here's a better one, with instructions down in post #7.
https://www.hondaaccordforum.com/for...ad.php?t=37663

Your 1992 has another funny valve on the opposite end if the intake-manifold plenum. That can also do something to the idle, but I never owned a 92 so don't know what do to with that other valve.

(I KNOW I wrote up something in the DIY area but can't find it right now.)

 

FIXED!!! I found a lot of side to side play in the throttle body. Replaced it with one from a wrecking yard and I was able to set the idle to spec.
Wow, gotta stick to the basics.
Thanks to all who replied while I was chasing myself in circles.

 

Side play? You mean the throttle shaft was loose?

If that was a big vacuum leak, fixing it should help more than just idle speed.