You are not alone -- intermitent stalling is a common problem with these cars. The most common causes seem to be bad fuel pump relays, fuel pumps, overload protection relays, fuel filters, fuel pressure regulators, vacuum systems, etc. ad naseum.
Do a search on "stalling 190E" and you will get a ton of information. Good luck!
1985 190E 2.3 8v
Rebuilt engine May 2002 (at 137,000 miles)
Lowered with Eibach springs and Bilstein performance shocks
An embarassing number of new parts
Pioneer DEH-200 head
Infinity Kapa Perfect 6.5" speakers in front doors
2 Sony Explod 8" subs in sealed trunk box vented through first aid kit
3 MTX amps, Callisto electronic crossover