Does anyone know if the Motronic does or can close the apeture for reducing idle? Or is the apeture mechanically set to a small amount and the Motronic only opens the opening size to increase idle?

If the ISV is unplugged, a spring keeps the valve in the "warm engine" position. I assume then that this position is the default (0 volts from the ECU?). So, I believe your second postulate is the correct one.

Jimmy

The reason I ask is that I have the same ISV on my car that I had with Motronic. I currently don't have any power going to it, so it'd be set to the default apeture size for idling(same as when I was running Motronic). The TB is the same. Yet with 034IIC I'm idling at 1700 rpm and can't get it down by leaning or riching the idle. I was idling at 800 rpm with Motronic.

I wonder if its ignition timing. IIRC turning the idle dizzy(timing) on older cars does effect the idle RPM without changing fuel or air. I might have too much advance. Especially if its at 1800 and the timing map is set to 0 or +15

It would seem that it makes more sense to have a minimum setting and method of raising it than to make everything more complex and have a "normal" in the middle of sizes and range both below and above it.

With these cars who knows, maybe that is how it works. But I would check other things first personally.