| 摘要 |
PURPOSE:To prevent an over-correction from occurring, by a method wherein an air-fuel ratio is corrected to the lean side on the basis of an air-fuel ratio feedback correction quantity immediately before correction, when correcting the air- fuel ratio to the leans side and ignition timing to the advancing side when the running condition of a vehicle is in a steady state. CONSTITUTION:In the titled controller, outputs from various sensors 3, 5, 6, 8, 9, 11, 13 for detecting the operating conditions or the like are processed by a controlling circuit 10, a fuel injection valve 12 is controlled to control the air-fuel ratio, and an ignition-controlling circuit associated with an ignition coil 16 is controlled to control the ignition timing. When it is discriminated on the basis of the change rate of the throttle valve opening and the change rate of the vehicle velocity that the operation of the engine is in a steady state, the air- fuel ratio is corrected to the lean side, and the ignition timing is corrected to the advancing side. In this case, when correcting, a target air-fuel ratio correction quantity is set on the basis of an air-fuel ratio correction quantity obtained at the time of feedback control of the air-fuel ratio, and the air-fuel ratio correction quantity to the lean side is restricted within the target correction quantity. |
