Help 1985-500SEL Manual Idle Adjustment??
 

Where is the manual idle adjustment at????? thanks for any help

I don't believe these cars first gen 126's have a manual adjustment.

I believe they have a regulation system of some type. I'm not all the familiar with the early 126 gassers though.

The adjustment screw is on the throttle body. It is preset at the factory and shouldn't need to be adjusted unless you have done a major change on the engine.

Look below the cruise control linkage bell crank and you can see it. Standing in front of the car, it will be on the left hand side of the throttle body, waaayyy down there on the front of the intake manifold where the air plenum connects to the manifold. It uses a locking nut (I believe it is an 8mm but it might be a 10mm) and a long, thin, straight bladed screwdriver for adjustment.

There's an idle control module mounted to the firewall. If you have a high idle, it may be out. Or you have a leak in your idle control valve, or your Over voltage protection relay (also on the firewall and will also light up your ABS light) is bad.