Misfire detecting device for internal combustion engine

摘要

A misfire detecting device for an internal combustion engine having a double-ended or single-ended distributorless ignition system is provided. The device comprises a first capacitor connected to a secondary winding side of a spark plug and in parallel to the spark plug, the first capacitor being charged by a voltage produced at a secondary winding side of an ignition coil and thereafter applying a voltage to the spark plug when a voltage at the secondary winding side drops, a second capacitor connected in series with the first capacitor and having a capacitance larger than that of the first capacitor to divide a voltage across the first capacitor, and a misfire detecting unit connected to a junction between the first capacitor and the second capacitor to detect a misfire on the basis of a decay characteristic of a divided voltage produced at the second capacitor. <IMAGE>