some advice needed....
 

hello all, this is my first post here. I just picked up a 73 450sl from a relative. The car has been sitting a few years and I have a feeling im going to be doing some work to it as it has pretty low miles. I would like to start with a good repair manual being I can work on cars.... also the last time I was in this car it had some sort of idle problem, in park it goes from 1000 to 2000 rpm like it has a big cam. Thanks for any replies...Dave.

High Idle Speed
 

Boraxman,

Adjust the idle speed with engine at running temp 80ºC via the adjusting screw (arrow) down to 700 RPM. If adjusting screw has no more adjusting thread, replace the auxiliary air valve (next to adjusting screw) and contour hoses. The thermovalve inside the auxiliary air valve loses its expanding property with time and 29 years is a long time....