I'm resurecting this as the symptoms have got worse. Tends to be reversing. The revs will drop then rev up once you take your foot off the accelerator.

When driving around parking lots, at about 20kph the car pulses.

I had a hunch so i disconnected the power to the purge valve and plugged the vaccuum line. The pulse is gone, idle is very rough like this.

I have also cleaned the egr and it is fine.

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1985 190E - Gone
1989 230E - Gone
1995 C200 - Gone
1993 280E 120000KM - Built like a brick, the best one yet