| 摘要 |
PURPOSE:To enable to control the air-fuel ratio smoothly, by stopping storing and learning for a prescribed while after rapid opening or closing of a throttle valve in controlling the air-fuel ratio in open-loop control region on the basis of a value stored and learnt as the center value of a correction value for the air-fuel ratio in feedback control region. CONSTITUTION:In operation of an engine, a control unit 4 controls the air-fuel ratio according to the operational conditions of the engine by way of open-loop control or feedback control based on the output of an O2-sensor 30. When the operational conditions of the engine is changed from feedback control region to open-loop control region, the air-fuel ratio in the open-loop control region is controlled on the basis of a value stored and learnt as the center value of a feedback correction value for the air-fuel ratio in the feedback control region. Here, arrangement is such that the above storing and learning is stopped for a prescribed while after rapid opening or closing of a throttle valve 14 disposed in an intake passage, whereby it is enabled to control the air-fuel ratio in the open-loop control region smoothly when the above-described transition in the operational conditions of the engine is caused. |
