| 摘要 |
PURPOSE:To compensate the delay of response in an air-fuel ratio feedback system from the detecting time of an exhaust gas air-fuel ratio by an O2 sensor to the operation of an air flow amount control valve. CONSTITUTION:In order to compensate the air-fuel ratio, air, which is not passing through a throttle valve 3, is introduced into the engine by an air-fuel ratio compensating circuit from an air cleaner 1 to a suction manifold 4 at the downstream of the throttle valve 3 through paths 9, 10 and the air flow amount control valve (EACV) 7. When the O2 sensor has detected that the air-fuel ratio of the exhaust gas is rich, a computer 8 increases the control current of the EACV 7 to enlarge the opening of the EACV7 and the amount of air, flowing therethrough, is increased. On the contracy, when the O2 sensor 6 has detected that the air-fuel ratio is lean, the computer 8 reduces the opening degree of the EACV7 to reduce the amount of air flowing therethrough. |
