System for detecting faulty ignition in combustion engines has magnetic pick-up producing analogue signals from variations in magnetic field caused by flywheel tooth gap distance difference

摘要

The system uses frequency analysis and has a magnetic pick-up (11) that produces analogue signals corresp. to variations in a magnetic field caused by a difference between the distance of a flywheel (10) tooth from the base of a flywheel tooth gap. A conversion circuit (12) digitises the analogue signal. A timer and counter (13) determine the time for the digital signals and the number of HIGH values. An ECU (14) receives these values to detect any misfires. An Independent claim is also included for an arrangement for detecting engine misfires.