KA24DE Bad idle, when coming to a stop.

I have the EXACT prolem as you, literally word for word. I’ve been told its becuase the IAVC butterflies are sticking so when you press on the clutch you idle drops but the butterflys dont move fast enough to compensate for the quick change in RPM and therefore choke the engine. I havnt got around to trying to clean them (with spraying cleaner in the hose) or try seafoam, im abit weary of the stuff so im not sure if i’ll try it. An ultimate solution would be to remove the IAVC and all emission related equiptment all together, if the IAVC is the problem that would be sure to solve it.

If you Fix it before me, make sure to post up what you did, and i’ll do the same.

will do.

OK so heres an update!

This weekend was a step by step kind of thing i guess.

First, Saturday morning, sprayed carb cleaner into the iacv hose (larger hose coming of the intake) for a good minute.

Second, Sunday morning same thing.

Third, tonight, replaced my sparkplugs and did the carb cleaner trick again.

Now from the second step i’ve done my idle dropping problem has seemed to dissapear…BUT, i’ve now come to the conclusion, i believe, that my MAF sensor has gone to shits. Considering my idle ONLY flutters from 700 - 300 than back up, than down, than up…etc etc, Only once i’ve come to a complete stop and just sat idle. SO i am pretty sure the last problem on my list is the maf sensor…correct?

Update on my end too. I emptied about half a can of combustion cleaner into the hose, let it sit then started the car. It seems to idle much smoother now. I think I got it warmed up enough to the point where the problem would start, and it was MUCH better, idle stayed around 700rpm for the most part. I’ll take it for a longer drive tomorrow and confirm that everythings better.

Martino, mine had the bouncy idle too, I’m not sure if it still does, like I said I’ll have to take it out for a nice long drive to really tell. From what I saw though the cleaning solved that too.

was your IAC connectors ever removed? I remember someone having a problem similar to yours and it was because they switched the connectors by accident

Yea sidewayz my first problem seems to have been solved, but now i just have the idle problem when sitting. Brendan suggested i try swapping a known good maf and/or ecu and try to see if that helps. I’m gonna do that after work and see how it goes…hopefully all is well.

And 3Vol…not that i know of.

was your idle fine before you replaced that tube with the duct tape? did you try putting the tube and res back on? it’s simple enough so it really doesn’t hurt to confirm this. i know i tried using tape when i first removed this but had problems with my idle so i just stuck the tube back on. no matter how flat or tight you have that tape on, i would expect the vacuum to eventually induce some flex into the tape, causing a rough idle similar to yours (because of the play that now exists). i’m just saying it wouldn’t hurt trying to attach something rigid to that opening rather than tape before you start suspecting other areas that require more time and effort. g2 make sure you not only check everything, but confirm for all suspect areas too for PITAs like this.

btw, a scary thought but it’s possible: let’s say that tape does give to the vacuum over time, it starts flexing more and more for each vacuum buildup, then all of a sudden when it fails, where does it go? right to the tb and in some unlucky cases, right in the mani, etc…

And what if i dont have the original tubing in my reach lol.
What would you suggest i plug the hole with?

I have my garage heated now, and man its toasty…so i plan to work on it late tonight since i dont have work ALL weekend.
And i’ll be fooling with the other motor i have sitting in the garage aswell…other ka, who wants to come tinker??? lmao

Your car is a 12- 14.5 volt at max system, with no major drain, there is nothing wrong with 12volts.