Like a Switch (W124/M103)
 

My '88 300TE behaves a bit poorly when cold.

Doesn't want to accelerate, and then (like a switch) suddenly catches and increases speed relatively normally.

Behavior is fine when warm.

Clearly something in the cold running circuitry is malfunctioning, but wonder whether this symptom provides a specific clue.

TIA

I would review what M.B.Doc had to say in the following thread. He discusses issues with a warm up regulator. Those became obsolete along the way and I'm not sure if they were still around when your MB rolled of the assembly line.

http://www.peachparts.com/shopforum/tech-help/122013-cold-hesitation-normal.html?highlight=cold

If your MB is not so equipped, I would consider:

a. thermostat - running too cold
b. ECT - engine coolant temp sensor. If defective, the ECT could be sending a "warm motor" signal early in the game, thereby keeping things too lean.

Thanks. Will check out.