My 1984 300D had developed a stalling problm; so my worthy trusted mechaninc said that the engine wasnt getting enough gas because there was a leak in the fuel system, consequently causing the engine to stall. So we replaced the fuel lines, fuel filter and fuel pump. I needed to clean out the fuel system aswell, to get it running in its optimum performance level. So i added half a bottle of snap diesel fuel system treatment to give it a boost. The problem; the car still stalls. It may correct itself as the fuel system becomes cleaner, but im not so sure. What eles could the problem be.