It's really hard to tell from here.

There are a variety of problems that can cause a rough idle - vacuum leaks, weak injectors, worn out O2 sensor, leaking air hoses, usw. In some of these cases, adjusting the mixture to spec will make the problem worse.

You need to take the car back to the mechanic, explain what is happening, and let him fix the problem. If he is unsure of what to test, find a mechanic with experience with your engine.

You could also go to Sears, buy a DMM with a duty cycle setting, get a 3 mm hex wrench, read the posts on how to do it, and try setting the mixture yourself. But a lot of folks have come to grief doing this.

Generally the mixture adjustment is sort of the crowning touch on a system that has its pieces working well - it is NOT a fix or compensation for other problems.

BTW - Is it a 380 or a 560?

__________________
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