The thermostat sounds like it is ok, there are at least two different thermostats made for the 190, one opens around 80 and the other around 70 or something, As long as it heats up to 80 and does not overheat, you're ok. When my thermo went out, it wouldnt even heat up to 80 on a cold day. 80=good. The stalling and not starting without throttle sounds like two problems. My fuel pump relay went out and it occassionally wouldnt start, and then sometimes stalled. The RPM's dropping, however, I have not been able to cure, yet. The car no longer stalls, but my RPMS almost always drop to a near die and the car shakes, then comes back. This happens usually when coming to a stop light and depressing the clutch after I have downshifted. My MB tech isn't sure, yet. Any clues anyone? Idle control stabilizer?
190E 2.3 8 valve 78k