Patent ID: 6349710
Filing Date: 2002-02-26
Classification: F02D

Abstract:
A combustion controller of an engine having a fuel supply system for supplying fuel, wherein the combustion controller selects a combustion mode performed by the engine from either one of lean combustion, in which an air fuel mixture leaner than a stoichiometric mixture is burned, and stoichiometric combustion, in which a stoichiometric mixture is burned, in accordance with an operating state of the engine, and feedback controls the air fuel ratio of the air fuel mixture when the stoichiometric combustion is performed using an air fuel ratio feedback compensating value, which is set in accordance with a component concentration in an exhaust gas, the controller comprising:a preliminary testing means for testing the fuel supply system and determining that the fuel supply system is in a normal state when one of a plurality of predetermined first conditions is satisfied, wherein the first conditions include a condition using the feedback compensating value; a lean combustion prohibiting means for prohibiting the lean combustion when the preliminary testing means determines that the state of the fuel supply system is ambiguous; and a main testing means for testing the fuel supply system and determining that the fuel supply system is in an abnormal state when one of a plurality of predetermined second conditions is satisfied, wherein the second conditions include a condition using the feedback compensating value.