Hey everyone (whoever's reading this thread) - I got some progress, great IDLE now, with TB fully closed, misfire all around, tons of CEL codes thrown, going to have to do something about all of that, but in the meantime - here are some progress pics with info.
I had 2 spare ICVs so I took them apart, and I realized that most of the used ones are most likely not good (read - crap). Most common failure is the O-ring on the ICV which is in the middle of it. Attached are pictures of me machining the idle control relocation plates and pieces of the ICV.
ICV is basically a weird looking shutter with pretty tight tolerances. The plastic housing is a two-part piece and one of them (one with an electrical connector on it) houses the electromagnetic piece which has two positions, open wide (cold start) and open partially (normal warm idle). The TB is fully shut during normal operation and ICV lets the air pass.
The second plastic housing piece has a press-fit and molded over shaft which has two grooves in it which are equidistant from both edges of it (Im guessing for simpler manufacturing). The main shutter element is a rare earth magnet which is epoxied or plastic molded together with the L-shaped metallic piece that actually acts as a barrier for airflow. And there is a tiny roller bearing press fit into the metallic side of it, which has a washer between the plastic housing and the bearing.
Now - the two plastic housing pieces are connected together using a bayonet type connection with a special groove for a sealing o-ring in between the two. There is a metal bushing that is likely heated and pressed to lock the two halves of the ICV connector in place. All 3 ICVs that I have (2 spares and one on the car) had bad O-rings, which is typical - the rubber hardens and it's typically a relatively high pressure differential area where the engine always wants to suck air in, so over time air passes through along with all the dirt and oxidizes the stuff inside, which is no good. Best course of action if an ICV is giving you problems is to take it apart, clean it out with IPA or something similar that takes most of the rust off, and reseal using a new O-ring, preferably covered in vacuum grease. (I believe the O-ring size is 27mm X 2mm, but I will check by trying some in there, didnt buy a replacement yet).
Oh and forgot the most annoying thing - there is a wave spring that keeps the two halves under pressure against each other so that it doesnt rattle around, so watch out for it. Kind of annoying when the magnet wants to attract it, as it is fairly basic steel. Overall a very nice design for a basic part that all cars use, one of the more complicated ones that i've seen so far.
Just sharing some info with the group
