| 摘要 |
PURPOSE:To improve the efficiency of air-fuel ratio control by a method wherein the quantity of an injection fuel is fed back on the base of the output of an O2 senser but when no feedback control is perfoamed, the quantity of the injection fuel is determined by using a predetermined coefficient of correction which is obtained at the time when the O2 senser is in its normal condition. CONSTITUTION:When an engine is in operation, an air-fuel ratio control circuit 17 operates an engine load obtained by the outputs of an air flow meter 11 and a rotational angle senser 15, the time of fuel ignition on the base of the number of revolutions of the engine and the time of fuel injection by a fuel injection valve 6 on the base of the temperature of sucked air. Further, the quantity of the injection fuel is fed back on the base of the output of the O2 senser 1 and when the feedback operation is not performed, the quantity of the injection fuel is determined according to the coefficient of correction used in the operation of the quantity of the injection fuel. In this case, the coefficient of correction obtained by the signal generated from the O2 senser 1 in the normal cycle are stored in sequence and when no feedback control is performed, the quantity of the injection fuel is controlled by using the last stored coefficient of correction. |
