1990 300E driving me up the wall

[aus124]

I just bought a 300E 124 1990 model with 103000kms on the clock, its a very nice car only thing is that on idle it vibrates the whole car (meduim vibration).

I tried everything that i read on the forums:

-adjusting the EHA screw (it seemed ok when i first put everything together but after that 2 minutes later it went back to the usual vibration)

- Adjusting the Mixture tried doing that in conjuction with the EHA adjustment but still no go ( did unitl i got around the 4V between pin 2 and 3).

- check all the vacuum lines everything seems ok.

- I tried taking off the ICV and cleaned it with carb cleaner it looked clean but ithought what the hell (might as well).

THe engine mounts seems ok.