I have a 02tls with 150k. Lately. I have random idle issues. At stops the rpm goes down to 500rpm and sometimes it comes back up to 750rpm but sometimes it just stays at 500rpm and the engine dies. I get no ecu code and I have a ODBII reader and have read no codes. The engine starts right back up and sometimes it repeat and sometimes it doesn't. Could it be the IAC valve?

I'm gonna change the sparkplugs later and ohm out the coils. Does someone have the resistance for proper coils? Can't find it in my helms.

 

just to update, I replaced the PCV valve with a new one. The old PCV didn't rattle freely as the new one. I replaced wtih a autozone brand for $5 because I didn't want to pay $18 at the dealer. I noticed the idle rpm is closer to 800rpm but will replace the IAC this weekend.

 

Dont replace the IAC just take it off and clean it well first. Also clean the TB with a good carb cleaner and a old tooth brush.

 

Finish replacing the IAC last night. I ended up removing the throttle body from the intake manifold. I wished acura/honda would have used an allen socket head screws instead of those standard philp head ones for the IAC body. I used my dremel to make a straight slot to use a flat screw driver to remove the throttle body. Since I spent quite a bit of time removing the type-s throttle bodies out of the way, I just replace the old IAC with a new one. The old IAC was pitch black and I was kinda tired already after cleaning the throttle to a nice shine.
Drove the car this morning to work and it is definitely better than before but I hope that was the culprit.

 

So does it idle normally now? How much did the idle valve cost?

 

It shouldnt need to be replaced. You can clean them. BUT if you feel the need to 127.00

 

It definitely idles better (normal) than before. After hard braking, the idle respone is faster.

I already bought the IAC from the dealer for $130 and I didn't really want to try to clean the old one, it was getting way to late at night. I'll try to clean out the old one and maybe use it next time or sell it.

IMO, the PCV valve probably should be replaced earlier since its cheap and easy to do. Cleaning the intake system and IAC on a normal schedule would also help.