Originally Posted by John Holmes III

Through 1975, MB used D-jet fuel injection on the 4.5 v8 models. It is a early comuterized fuel injection, and uses a analog computer. The first model to use D-jet were 1969 3.5 v8 models(230 hp).

It was a expensive and complicated system, so MB switched over to CIS for the 1976 model year for all v8 motors, including the 6.9 M100 motor used in the 450SEL 6.9.

I would be very aware of rich running on 1975 model 450SL's beacause of the thermal reactors mounted on each exhaust manifold. They can melt down.