I have never owned one, but judging from the 1990's M-B gassers I see in the junkyard, most used the Bosch Jetronic fuel system. For a mechanical engineer like me, it is a wonder. A plate is pushed by the inlet airflow to control the fuel flow, which is distributed to each injector by a "fuel distributor". It is all mechanical I think, like a distributed carburetor on steroids. First time I saw one was when I helped a girl with her 1990's VW Jetta (bad fuel pump, ran great on starter fluid). To work right, everything must be pristine since the airflow force is weak. I think the flapper pivot used jewel bearings. Downside of course is repairs, and parts are astronomically priced for M-B and BMW. Many people convert these gassers to more modern electronic fuel injection and sparking, using megasquirt and such.