摘要 |
In an apparatus for controlling an air/fuel ratio of a general-purpose internal combustion engine using mixed fuel containing alcohol and gasoline and operated at a desired engine speed inputted by the operator while a throttle opening is regulated such that a detected engine speed converges to the inputted desired engine speed, a fuel injection amount prepared for mixed fuel is increased/decreased when a load is kept constant and the output air/fuel ratio (at which an output of the engine becomes maximum) is estimated. A rate of alcohol contained in the fuel is estimated from the estimated air/fuel ratio (S300 - S308, S312, S316 - S320, S324, S326) and the fuel injection amount is corrected based on the estimated alcohol rate (S310, S314, S322, S328), thereby determining the fuel injection amount appropriately in accordance with the estimated alcohol rate.
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