PURPOSE: To eliminate any variation in air/fuel ratio to aim at smooth operation by correcting first correction values according to oxygen density in exhaust gas in response to the deviation of respective secondary correction values caused by the average of the first correction value in each operation area.
CONSTITUTION: An electronic control unit 44 controls at least a plurality of fuel injection valves 16 provided at an intake manifold 14 according to at least signals detected by an 02 sensor 40 provided at an exhaust manifold 14 to feedback-control air/fuel ratio. The electronic control unit 44 calculates first correction values according to oxygen density in exhaust gas, and also averages the first correction values in a plurality of operation area to calculate secondary correction values thereby. In this case, when the operation area is shifted from one to the other, the first correction value is corrected in response to the deviation of the respective secondary correction values memorized in the respective areas. Fuel supply quantity is corrected by the first correction value thereby.
SAITO YASUHIKO
KOJIMA ATSURO
| JPH01130033A | 1989-05-23 |