Yikes! End of your rope? Don't hang yourself with it!
I love the 190 series. Had a problem similar to yours with another car. Turns out the alternator (or was it the generator) was bad. So when I first drove the car it was runing fine but was using the battery. In just a few short miles (depending on the accessories in use at the time) it would stall because the battery would be drained. Had nothing to do with the fuel.
The other explaination could be vapor lock if your fuel line is near a heat source. But then again, I think the EFI engines didn't suffer this malady. Hmmmmm.
Hope this helps! Good luck.