Your car IS fuel injected. Remove your air filter housing and you will see the mechanism including the fuel distributor.

IRT mechanics, I believe you need a new, independent Euro/German car specialist. Based on your original posting, your present mechanic does not have a clue about your car. The dealership is dicey since your car is 26 years old and most dealers no longer have mechanics with a lot of experience on old Benz.

Unless you live on the moon, there is an independent shop somewhere in the area that specializes in old Benz. Don't give up on the car. The engines are basically as tough as they come and will go hundreds of thousands of miles without major repair so long as you do basic preventive maintenance.

As you know by now they are rewarding cars to drive. Mine was literally my daily ride to work and to play until my wife totalled it. She was unhurt proving that the body and chassis is equally tough. Replaced it with something even older and tougher, a W123 diesel coupe.