Hi Steve, marry Xmas first of all!
I checked the EHA again and watched for the polarization this time. KonEoff, I first had a stable 10mA which then switched suddenly to a stable 19mA after 5-10s.
Eon, the current was between 0 and -8mA, sometimes even +0.2mA. When the current is around 0, the engine sounds like in unloaded idle. However, as I described above, the revs decline periodically and the engine sounds as if it would be loaded. The EHA current then quickly rises up to 8mA. I would guess, it sounds abou 1s unloaded and 2s loaded.
I also checked the spacing of the sparks and adjusted the spacing to 0.8mm (the manual states 0.8, but MB mechanics sometimes adjust it to 1mm for a better idle). When I started the engine, the idle felt so gentle. Amazing, that's what I was looking for. However, finally I discovered that I had forgot to reconnect the EHA. And after reconnecting I had the same rough idle back again. =-(
What do you think, Steve, isn't -8mA during idle a bit too much?