Hey I have a B20 Vtec with a turbonetics turbo on it. The car runs great but i am having one problem and thats an idle problem. Sometimes when i come to a stop, the idle jumps up to 1300 and then idles really bad and throws a check engine light for an idle air control valve. I have changed that out and still have the same problem. Any ideas??? This only happens sometimes and then i turn the car off and back on, and its fine for a while. Also when this happens the car jerks really bad when i let off the gas and back on it. Any help on this would be appreicated...thanks

 

one other thing i just unplugged the IAC and the car idles perfect so why would that be??

 

idle might be turned up too high or too low, try adjusting it a couple of times and see if that helps

any vacuum leaks any where?

if it idles perfect when u disconnect the other iacv you got, it might be possible that the other is bad too

 

no vaccum leaks anywhere but why would it idle perfect when its unplugged and why would it screw up when its plugged in

 

car does the same thing in my b20 non-vtec when its plugged in it jumps up and down but when its unplugged its fine but it throws a check engine any more info ppl?

 

alright i unhooked the IAC and drove the car and it ran fine...any explanation for this

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PrettyLude &raquo;</TD></TR><TR><TD CLASS="quote">idle might be turned up too high or too low, try adjusting it a couple of times and see if that helps

any vacuum leaks any where?</TD></TR></TABLE>Make sure you don't have vacuum leaks.

It's not supposed to idle perfect when you unplug the IACV. It's supposed to idle real low, almost stalling. So it sounds like your idle is adjusted too high.

 

i drove the car tonight and it jerks pretty bad but the idle is good..do you guys think the IAC is bad or what? is it worth getting a new one. When i plug it back in the idle jumps again

 

get one a new one and seee

 

well what do you think it could be...thats not a cheap part to just go out and buy

 

take out the IACV and clean it with carb cleaner. I was throwing a P0505 which is idle system malfunction (pretty much replace the IACV). I had the exact same symptoms. Very jerky when you go from no throttle to throttle or vice versa. The ide was high (1500) and very jumpy especially if you just touched the throttle and held it. I cleaned out the IACV and havent had the light come on so far.(about a week) Try cleaning it before you shell out $160 for a new one. there very expensive, atleast for my b16 it is.

 

what year was your B16 and what happened when you just sit at idle like at a stop sign

 

OK ill be real specific with what happened. The car is a 99 Si with a B16a2. I was driving on the parkway and when i got off at the exit ramp and stopped at the light the check engine light came on and the idle jumped up about 300 - 500 rpms and idled really poorly. It was also very jumpy and jerky going from no throttle to throttle and vice versa. I pulled over and checked the code and it was P0505 Idle Control System Malfunction. I reset the code started back up and continued driving. It ran fine then. About 20 minutes later I was at a very long red light and the CEL came on again, and again idle jumped up about 300 - 500 rpms, and the idle was very unstable. It would idle at like 1000 or so and go up to 1200 and go back down to 1000 and back up as long as the car was idleing. If you just touched the throttle and held it slightly down it became much worse but cleared once you hit about 1800+ rpm. All of this is in nuetral. It was fine while actually driving except for being a little jerky and when stopped. I did some searches and made a post on here and found that the problem was the IACV. I went to go buy one but it was 169.99 +tax. I did some more searches on google and found a how to on cleaning it and figured let me do this for free and see if it works before i spend almost $200. (HERES THE LINK)

http://www.superhonda.com/foru...44463

I first reset the code again, took off the IACV, cleaned it and reinstalled it. The whole process takes about 20 minutes to remove, clean, and reinstall. I took it out for a 30 minute test drive and it was fine and i have been driving for about a week so far and it has been good. Hopefully the light doesnt come back on and everything is fixed, but as of now it runs like new. Hopefully I helped you out. Good Luck!

 

hey man thanks a lot. that sounds a lot like what mine is doing right now. I will be sure to try that and maybe something good with become of it. If anyone else has anything to add then please fill me in...Thanks

 

Great thread! This just saved me $175+ Now I can go buy those spinner hubcaps I saw at Pepboys.