Patent ID: 6634220
Filing Date: 2003-10-21
Classification: G01M

Abstract:
An apparatus for detecting a misfire of an internal combustion engine comprising a controller that:determines a starting condition of the internal combustion engine, the starting condition is a condition of the internal combustion engine when the internal combustion engine is initially started; counts a total number of rotations of the internal combustion engine; detects a misfire of the internal combustion engine; calculates a rate of misfire using data from detecting said misfire, the rate of misfire being a number of misfires per a predetermined total number of rotations; sets a basic rate of misfire in response to the determined starting condition of the internal combustion engine; and determines an abnormal condition of the internal combustion engine when said calculated rate of misfire is greater than the set basic rate of misfire; wherein said controller determines the abnormal condition of the internal combustion engine by a coolant temperature or an intake air temperature of the internal combustion engine.