Re: Mercedes 124 stottert und bockt manchmal! Ident: WDB1240431A.

Loose translation:

1987 124 model

After the car is parked for 3 days or longer, never less, it has a
problem.

I start driving it - normally - for 2 to 4 km and then, just as the 
engine temperature reaches 80 degrees C. (normal), it starts to lag, 
buck and backfire - as if something is stopped up - insufficient air or 
fuel.

But the engine keeps running and after another 1 to 3 km runs normally. 
It also clears up if the engine is shut down and restarted. This never 
occurs if the car is driven more frequently than three days.




Suggestion:

I believe the first thing to check is the "over voltage protection 
relay" - it has a fuse on its top.