Patent ID: 6298717
Filing Date: 2001-10-09
Classification: G01M

Abstract:
A device for detecting misfire in an internal combustion engine comprising:various sensors for detecting operation conditions of the internal combustion engine;an operation region detection means for detecting an operation region of said internal combustion engine from said operation conditions;a control parameter operation means for operating control parameters of said internal combustion engine based upon said operation conditions;an ignition device for igniting said internal combustion engine relying upon said control parameters;an ionic current detection unit for detecting an ionic current generated upon the ignition of said internal combustion engine;a first misfire judging means for judging the misfire in said internal combustion engine based upon a change in a time of revolution data of said internal combustion engine included in said operation conditions;a second misfire judging means for judging the misfire in said internal combustion engine based upon said ionic current; anda misfire judgement selection means for selectively using the first misfire judging means or the second misfire judging means depending upon said operation region.