| 摘要 |
PURPOSE:To prevent any drop of torque and realize smooth acceleration so as to alleviate a torque shock by correcting a fuel injection quantity on the basis of a suction pressure in such a manner that an air-fuel ratio turns into a lean side when a suction characteristic changing means is switched together with an increase in suction quantity. CONSTITUTION:A suction passage 8 downstream of throttle valves 11 is branched into a primary suction passage 8P and a secondary suction passage 8S. A suction changeover valve 15 is disposed at the inlet of the suction passage 8S. When a controller 20 controls the suction changeover valve 15 together with an injector 12, a fuel injection quantity is determined according to a low speed map in a low speed region A where the suction changeover valve 15 is closed or according to a high speed map in a high speed region B where the suction changeover valve 15 is open. Additionally, in the vicinity of a set engine speed (No) where the suction changeover valve 15 is switched from an open state to a closed state, and vice versa, the fuel injection quantity at the time of the switching is corrected to be decreased in such a manner that an air-fuel ratio turns into a lean side at the time of acceleration while it is corrected to be increased in such a manner that the air-fuel ratio turns into a rich side at the time of deceleration. |
