| 摘要 |
PROBLEM TO BE SOLVED: To properly learn an air-fuel ratio even when a short term air-fuel ratio deviation, such as the temperature characteristics of an injector, occurs. SOLUTION: An ECU 30 has a plurality of air-fuel ratio learning zones corresponding to the operation region of an engine, learning correction is executed at each leaning zone by an air-fuel learning value determined from an air-fuel ratio feedback correction amount to cause an air-fuel ratio to coincide with a target value to control a fuel injection amount by an injector 18. Further, especially, a CPU 31 in an ECU 30 calculates and updates one by one a MAX value and a MIN value of an air-fuel ratio total deviation amount in addition to an air-fuel ratio learning value when a given air-fuel ratio learning condition is established, and store the results at each leaning zone. Further, during the staring of an engine, the CPU 31 averages the MAX value and the MIN value stored during preceding operation and the average value forms the initial value of the air-fuel learning value.
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