Throttle linkage & throttle microswitch question - '91 300CE

[rgnprof]

I have just recently pulled my fuel distributor, checked the injectors etc and have just got my car back together. Seems to have fixed some problems I was having with the fuel mixture as I am now able to get the car in closed loop. Car is idling fast (1500 rpm in P and drop to 750 in D). I think my linkage is off...

When I manually close the throttle linkage and activate the Microswitch (see link below) by moving the roller wheel lever closer to body of the switch, the idle drops to normal and stays there.

Question: should this microswitch be 'closed' at idle? The switch is clicking when I move the roller wheel lever so I think the switch itself is fine, but I think somewhere along the recent removal and installation, the linkage may be off. But, I'm not sure how to adjust it...

Any advice?
Thanks.
Ryan