Skiing is a great way to spend this part of the year. I'm jealous. I was a daily cross-country skier in my much younger years. I suspect that the ski areas are locked down here, though I haven't looked.
It's late and I'm not going back downstairs to play, but I can tell you that
1. I gently tapped on the bolt head with a hardwood handle and the rack will now move freely. It spins the measuring valves for all six cylinders.
2. There doesn't seem to be any sort of natural rest position for the rack- it's not spring loaded in either direction.
3. Indeed, none of the regulatory or control mechanisms seem to affect the rack- including the throttle and stylus. I need to look at this again.
4. I understood the space cam/stylus function backwards, just by assumption. However, the meaty portion of the space cam never lies under the stylus. The first picture last time was throttle closed- as CCW as it goes. Should it rotate further? Not properly installed?
5. Cold enrichment- Belt, suspenders, and staple gun.
a)there is a solenoid (currently inoperative) mounted on the back cover that pushes on a plastic lever (sticking up out of the top of the opening in the below picture) that pushes directly on the main rack adjustment screw. Activated by the thermo-time switch. Pump expert says this one is not necessary if the cold start injector is working.
b) there is a seventh fuel injector on the intake manifold, also connected to the thermo-time switch.
c)There is also an auxiliary air valve that sits on top of the MFI pump that works in concert with a cold enrichment function activated through rods and levers. Controlled by the temperature of a special coolant circuit for just this purpose. This is Mercedes-Benz, after all.
6. No fuel cut-off solenoid. In fact, with the auto transmission there is a mechanical device to dampen the fuel cutoff at zero throttle.
Maybe lots more cleaning required. I've heard ATF is the bomb for such things. Unfortunately, I just recycled all of mine.
This has become an adventure. Thanks, Jonny!