Correct position of Idle Control Valve - 1987 Mercedes 190e 2.3

[Eidetic57]

Hi;

I have a 1987 Mercedes Benz 190e 2.3 Liter that I am trying to re-assemble.

I am trying to obtain the following information -

1. My current Idle Control Valve has an arrow on one of the two fittings. Should it be pointing upwards towards the air filter housing, or down towards the throttle body.

2. Considering it is a "Pintle Valve" does it matter which way it points.

3. Does the idle control valve on the 190e operate, either in full open or full closed, or does it open partially depending on the voltage it's receiving

Thanks,

Eidetic57@hotmail.com