| 摘要 |
PURPOSE:To maintain a purifying function of a ternary catalyst, by correcting a decrease of CO amount due to an increase of alcohol content with air-fuel ratio, which is in a little rich side from the theoretical air-fuel ratio, serving as the target in accordance with the alcohol content of fuel. CONSTITUTION:An electronic control unit 4 arithmetically controls the valve closing time of an injector 36 on the basis of detection values of an O2 sensor 1, throttle valve opening sensor 31, intake absolute pressure sensor 32, water temperature sensor 33, intake air temperature sensor 34 and a crank angle sensor 35 or the like. When activation of the O2 sensor 1 is finished, this time feedback correction coefficient is obtained from the preceding time correction value and feedback correction coefficient based on an O2 sensor output obtained from a PID control. When this time feedback correction coefficient increases to a predetermined value or more, an alcohol content in fuel is decided to be high, and the feedback correction coefficient is corrected by reading the alcohol content stored in memory corresponding to the feedback correction coefficient.
|
