| 摘要 |
PROBLEM TO BE SOLVED: To control an air/fuel ratio with high accuracy according to changes of a throttle opening within a low opening region, without especially increasing the number of learning regions. SOLUTION: An electronic control unit(ECU) 30 of an air/fuel ratio control unit for an engine 1 determines the basic fuel injection quantity, based on a throttle opening and an engine speed. Through compensating the basic fuel injection quantity based on a learned value computed for each of a plurality of learning regions to be determined by the throttle opening and the engine speed, the ECU 30 performs feedback control, so that an air/fuel ratio of a combustible mixture supplied to the engine 1 becomes equal to a predetermined stoichiometric air/fuel ratio. When the throttle opening is changed within a low opening region of a throttle valve 5, the ECU 5, the ECU 30 computes a learned theoretical value, in such a manner it predicts the value in the low opening region based on an hourly change of the throttle opening, the throttle opening, and the engine rotational speed. Furthermore, the ECU 30 compensates the basic fuel injection quantity based on the learned theoretical value.
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