The idle is electronically controlled, and the mixture is adjusted by measuring the on-off ratio. Lots of posts on this, try a search.

To raise the idle, you can you can:

- uplug and bridge the connector at the back of the rear of the right cylinder head. This will make the idle relay think the engine is cold

- unplug idle control valve at the front of the intake manifold - idle should go to 1200 rpm or so

- adjust the throttle linkage to open the throttle plate a bit.

__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe