Replace all the rubber connectors on the all vacuum lines.

Check the manifold for leaks by spraying carb cleaner around the gaskets and listen for change in idle. Spray some cleaner around the injector seals to see if any of them are leaking.

Read the posts about "cracking" the lines on the fuel distributor to see if you can isolate the cylinder(s) causing the problem.

__________________
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