I may have a bad IACV...

[AwwsChwA]

Ok, here's the deal...

my 91 CRX Si has a quirky idle when it's warm. I've already replaced the coolant temp sensor, cuz I was told that that sensor can cause the idle to be erratic if it's faulty. But, the idle is still a little screwy. For example, when I come to a stop light, sometimes the engine goes waaaaaaaaaay down almost zero RPM, just barely turns over, and after 2 or 3 seconds it comes back up to normal. Other times, it'll go waaaaaaaay down to almost zero, and actually stall out.

This doesn't happen every time I stop, but I'd say maybe 1/3 of the tiem it does this. The stalling thing is more rare, maybe 1/20 times it'll actually die out.

I've been told by a couple mechanics that, if the Idle Air Control Valve goes bad, that symptom can happen. Also, I was told that Honda IACV's don't respond well to cleaning, they just have to be replaced once they get old and die. Anyone ever had to replace this? The engine has 182k on it, its a stock D16A6.

I also need to scrape all the black crap off of my throttlebody butterfly, it's pretty bad. All the so-called cleaners don't work worth a sh11t. So, I'm just gona get in there with a toothbrush and some compressed air and try to get it clean. Any ideas? Thanks

[Hondaman]

The cleaners won't clean your throttle body by the butterfly, there is no way it can go against the stream of incoming air. The cleaner will only clean your injectors and valves. You may have to take the throttle body and intake manifold right off the engine to give it a good cleaning. Other wise you can run your engine and spray little bits of carb cleaner in the throttle body, but that can seriously mess with your O2 sensor and cat converter.

[doctorsohc]

Originally posted by Hondaman
The cleaners won't clean your throttle body by the butterfly, there is no way it can go against the stream of incoming air. The cleaner will only clean your injectors and valves. You may have to take the throttle body and intake manifold right off the engine to give it a good cleaning. Other wise you can run your engine and spray little bits of carb cleaner in the throttle body, but that can seriously mess with your O2 sensor and cat converter.

They make intake cleaners specially formulated to not hurt O2 or the cat. I took mine off and cleaned it, but have had good luck cleaning it on the car as well - with the engine off, I just pry open the throttle and spray some cleaner on a towel and wipe off all the crud. Works much better than flooding your motor with cleaner. I also learned the hard way that you shouldn't clean the IAC valve - I had to buy a new one as well.

[aero3685]

Let us know if that is the IAC valve, cuz my accord w/190k on it does the same thing, except its just the low idle, maybe 3-400 rpm, and doesnt stall, but im sure if I let it go it will get there. And yeah, it only does it 1/4 to 1/3 of the time.

[Hondaman]

Originally posted by doctorsohc
They make intake cleaners specially formulated to not hurt O2 or the cat. I took mine off and cleaned it, but have had good luck cleaning it on the car as well - with the engine off, I just pry open the throttle and spray some cleaner on a towel and wipe off all the crud. Works much better than flooding your motor with cleaner. I also learned the hard way that you shouldn't clean the IAC valve - I had to buy a new one as well.

Good ideas!!

When I meant that cleaners won't clean the upper throttle body, I meant the stuff you put in your gas tank. Sorry if I confused anyone.