BMW 318/325/M3/525/535/M5 1989-1993 Repair Information



The tune-up as once known is obsolete. With the present electronic engine controls, the need to manually adjust the operating parameters of the ignition system has been done away with. The Digital Motor Electronics (DME) engine control system your car is equipped with, monitors the operation of the engine with sensors and automatically adjusts the operating parameters as the engine runs. This leads to better fuel economy, less exhaust emissions and better engine performance. The days of adjusting timing, mixture and idle speed are over. The tune-up on your car consists of changing the spark plugs and inspecting the rest of the system.