Rough Idle, Black Smoke.

[BMW BMXER]

The ICV regulates the amount of air that bypasses the throttle. More air means a higher idle speed.
The ICV is a solenoid, or linear motor. It has a coil of wire which creates a magnetic field, moving the plunger.
The early 2-wire VDO ICV's are single pole. They have a spring which holds the plunger open. When current is applied to the terminals, the ICV closes.
The later Bosch 3-wire ICV's are two-pole. There are two coils of wire. The normal position is half-open. Current applied to one coil will open it further. Current applied to the other coil will close it fully.
The later design is superior because if it fails electrically it is in a fairly 'normal' idle position. With the early VDO ICV, electrical failure means the ICV will be wide open, causing the 2000+ RPM idle situation.
The two ICV designs are not compatable. The VDO ICV is controlled by a separate control unit. The Bosch ICV is controlled by the Motronic unit (ECU).

Thanks! I hate fixing things that I don't know how they work.

[BMW BMXER]

I cleaned the icv with some shit called xlylene that my dad said "should so the trick" the idle isn't lumpy anymore but still loopy.

It's actually "xylene". I hope you wore gloves and didn't breathe the fumes. It's what the English call a "carcinogen." (Just as nearly all benzene derivatives are).

But anyhoo... glad you got your prob fixed. What do you think it was that fixed it?

My idle isn't really all that stable... but I've yet to encounter an M10 with a perfect idle...

Ive breathed some pretty bad fumes in my day but that shit took the cake so I wore a mask.

I cleaning the ICV generally yeilded the fastest/best short term results. (lasted about a month to two each time)