Apparatus for detecting misfire in multicylinder internal combustion engine

摘要

An apparatus for detecting misfire in a multicylinder internal combustion engine, comprising a sound pick-up transducer disposed in the exhaust passage of the engine or a chamber communicating with the exhaust passage for the purpose of detecting exhaust sound, an integrating circuit for integrating an electric output of the transducer in synchronism with the rotation of the engine and a comparison circuit for comparing the output of the integrating circuit with a reference signal, thereby misfire being detected on the basis of an output of the comparison circuit.