Air-fuel ratio control system for automotive vehicle equipped with an air conditioner

Claim 1

An engine control apparatus for controlling an air-fuel ratio of an air-fuel mixture supplied to an engine during use of an air conditioner mounted on an automotive vehicle, comprising: air-fuel ratio determining means for determining the air-fuel ratio of the air-fuel mixture supplied to the engine; fuel supply means for supplying fuel to the engine so as to meet a given air-fuel ratio; air conditioner operating condition determining means for determining a drive torque of a compressor used in the air conditioner, the compressor being driven by the engine during use of the air conditioner, the air conditioner operating condition determining means determining the drive torque of the compressor using a given relation to a value of an amount of current supplied to an air blower disposed in the air conditioner and correcting the determined drive torque to provide a corrected drive torque based on at least one of a plurality of parameters indicative of an air temperature cooled by the air conditioner, an outside air temperature, and an engine speed; and control means for controlling the fuel supply means to enrich the air-fuel mixture supplied to the engine so as to modify the air-fuel ratio determined by the air-fuel ratio determining means to a richer target air-fuel ratio according to an increase in the corrected drive torque of the compressor determined by the air conditioner operating condition determining means, the increase in the corrected drive torque being produced by an increase in load of the engine during use of the air conditioner.