I dont know if it can be rebuilt, but on my 300E, I removed it and soaked it overnight in carb cleaner. You wouldn't believe the amount of crud that came out of it.
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1987 mercedes 300E
1989 engine(long story)
1995 e320 conversion(hated the 300e grill)
HID/Xenon (D2S)
Keyless Entry
Monochromatic Paint (Custom Blue)
Smoked Tails
Flat Badged (front)
Debadged (rear)
custom "carbon fiber" console
18 inch HP EVO rims
Sold! Now I drive a Monte Carlo SS
Thanks Mike, I did the same thing and my car ran amazing for about 2 days. The idle was great too! On the 3rd day my idle dropped again and I'm back to the drawing board! That's why, I want to know when it's time for a new ICV and or can it be rebuilt???
Have you checked the little rubber hoses under the hood?
You might have a vacuum leak somewhere. The little rubber hoses are cheap, and I would do that before shelling out $$$ for an ICV.