I’ve been trying to resolve the hunting idle issue for some time. I’ve tried using Seafoam before w/ limited success. In previous cars I have had great success to reduce sticky throttle and smooth out idle. It seems this is the only sure way to clean out the gunk that’s built up in the ICV.

As usual, the planned time of 1 hr got bloated to 4 hr because I never done this before and there are a bunch of ‘undocumented’ procedure that must be done before I can get to the ICV and the TB.

Ok, so here goes the overview:

1) Remove the airbox
2) Remove the MAF
3) Remove the 1st section of the airduct
4) Remove the cabin filter + housing
5) Remove the plastic panel around the left strut tower (Need for clearance!)
6) Remove the intake resonance valve
7) Remove the ICV
Clean ICV + TB
9) Assemble in reverse

Well, that’s the way i found easiest, after fumbling and making so many mistakes. But hey, I’m going thru the pain so you guys doesn’t have to, rt? First remove the air box

Getting the 1st section of the air duct out is a bit complicated. I later realized that I really should have removed all the other stuff that are in the way first: cabin filter housing, intake resonance valve and plastic baffle around the strut column.

Here’s the intake resonance valve:

Here’s the plastic baffle out:

It was pretty hard to get the metal straps out from the Y air duct as they were facing toward the rear. Using flexible connector and various adapters I was able to get it loose enough. Pull out the duct.

You can see here the intake manifold resonance valve (top black hole), idle control valve intake (smaller hole on the right) and the throttle body (lower opening). Remove this bracket nut and move it out of the way first:

Unplug, unbolt, and wiggle out the ICV together w/ the brackets.

Here’s the view with the ICV removed.

Look at the gunky stuff build up inside:

I use throttle body cleaner + Seafoam Deep Creep. The throttle body cleaner remove most of the gunk pretty well. The Deep Creep remove some but it also lubricates, so I use that last.

Clean it as best I could:

I prop the throttle open w/ a socket extension section wrapped in electrical tape so not to damage anything. Again I use throttle body cleaner + Deep Creep to clean and lubricate the TB. I use plastic bags and some rag stuffed under the TB to absorb any run-offs.

Wipe every thing clean before reassemble, in reverse order. The only thing I make sure of is that the Y air duct, I made sure that the screw for the straps are pointed up so next time it’ll be easier to get to if needed.

Well, went for a test drive, not bad, the idle is definitely way smoother. Throttle response seems to be better as well, but maybe just my head. At stop light the engine
runs so smooth, just as it should be. I haven’t noticed any rpm hunting yet, but I haven’t drive the car extensively yet.

Hope this helps you guys out.

Souce: e46fanatics.com
Author: peanut_man
Full link: http://forum.e46fanatics.com/showthread.php?t=615503

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