| 摘要 |
PURPOSE:To prevent rough idling operation of an engine and generation of irritant odor from catalyst, by stopping feedback control of the air-fuel ratio and correcting the air-fuel ratio to make air-fuel mixture lean when the vehicle is stopped and the engine temperature is higher than the ordinary level. CONSTITUTION:When an engine is in operation, an engine control unit 48 controls the air-fuel ratio to an aimed value by way of feedback control by obtaining a datum injection pulse signal Tp from the amount of intake air detected by an air-flow meter 14 and the engine speed detected from a primary ignition signal Ig and controlling operation of an injector 26 by correcting the signal Tp appropriately according to the output of an O2-sensor 30, etc. Here, if it is detected from the output of a vehicle-speed sensor 44 that the vehicle is at rest and the output of a water-temperature sensor 36 is higher than an ordinary value, feedback control of the air-fuel ratio is stopped. Further, control is executed to make air-fuel mixture lean by reducing the air-fuel ratio correction factor by about 5-10% uniformly, for instance, by reducing the correction factor by 5%. |
