Hey, I can chime in here. I helped Visal adjust his duty cycle and he (we) were definitely getting the adjustment screw to turn. I've done this on my own car and I know how it feels when you get the screw, it is an easy thing to confuse when you've never done it before but I have and when you get the screw there is noticeable resistance. Anyway, we managed to change the nature of the idle (to a rougher idle) by messing with it so something is changing, but the meter read 82% no matter what. When you turn the car on it's 50% and slowly climbs up to 82 and stays there. WOT on the throttle it goes back to ~50% and then slowly climbs back up during idle. On my 190e 2.6 this worked text book, not so on his CE.

__________________
1992 190e 2.6