On 1993 BMW M50 Engine series, the ignition timing is electronically controlled and not adjustable using the Motronic 1.3. The DME control module uses engine load, engine speed, coolant temperature, and intake air temperature as the basic inputs for timing control. A direct ignition system is used. Individual coils are mounted directly above each spark plug. Each coil can be selectively controlled by the DME control module on a cylinder-by-cylinder basis.The following schematic shows the 1993 BMW M50 Engine Motronic 1.3 Ignition System Wiring Diagram which consists of: battery, ignition switch, ignition coil, distributor, spark plugs and motronic control unit.