I have a weird problem with the engine of my W123 (the engine is gasoline, 2L, 80kW with a Stromberg 175CDT carb).
When the engine is cold (less than ~50C or so), it acts weird. When I want to accelerate from slow speeds (first, second gear) and press the accelerator, the car delays a second or two and then jumps forward. This happens once or twice and then does not happen until I turn the engine off and then start it again.
EDIT: As it is now much colder outside, I think I have found the actual problem symptom. When I start the engine, while it is cold, if I quickly press the accelerator (without the car being in gear), the engine just stops. After a minute or so of warming up it works properly.