Trouble is, if the car starts easily and warms up OK, then the probable causes of erratic idle are FD, injectors, and vacuum leaks.

And, fixing problems like this is sort of a guessing game unless you happen to have a bazillion dollars worth of test equipment. You start with the cheap stuff like plugs, wires, and injector seals and work your way up to the expensive.

But if you are going through a liter of oil in 600kms and getting white smoke (coolant=head gasket) on startup, then it's time to think about a head rebuild.

__________________
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