| 摘要 |
PROBLEM TO BE SOLVED: To efficiently reduce NOx from the beginning of a restarting by correcting an air-fuel ratio in the restarting to be temporarily richer than a target value in compliance with an integrated value of an intake air amount or a stopping time from a stop of fuel supply to an engine till the restart. SOLUTION: When it is determined that it is not in a fuel-cut condition while the number of idle revolutions is a reference value or more and a feedback control condition is established, it is determined whether operating conditions till the previous time is in a fuel-cut condition or not (S1-S4). If it is determined that fuel injection is restarted for the first time, a correction value PLCLP for a proportional part P of an air-fuel ratio feedback control constant found from an integrated value SQa of an intake air amount integrated during a stop of an engine is corrected with a correction coefficient KPLVTC based on a cam actuation angle, and a feedback control constant α is set so that an air-fuel ratio is shifted greatly to the rich side (S5-S8, S14). Including the feedback control constant α, a fuel injection amount is computed (S16), and then, control for enriching the air-fuel ratio is carried out. |
