The engine wiring can degrade because the insulating material falls off leaving the bare wire exposed. This can cause many problems depending on which wires are exposed and what they touch.Google+
Car Problem Reports
Mercedes-Benz 300E Insulation Degrades on Engine Wiring Harness and Leaves Conductors Exposed
Mercedes-Benz 300E Problem
Visitor, 1993 Mercedes-Benz 300E, 93,000 mi
starting the car in the morning no problem,but after I shut off the engine it will not start,it will eventually start but it means me holding the throttle fully down and crancking the motor like its flooded.