| 摘要 |
PROBLEM TO BE SOLVED: To perform highly accurate air-fuel ratio control by properly setting a learning frequency and preventing mistaken learning. SOLUTION: Fuel vapor generated from a fuel tank 7 is temporarily adsorbed through a tank inner pressure adjust valve 30 on a canister 13, and the adsorbed fuel vapor is discharged through a purge solenoid valve 16 to an engine intake system. In the fuel tank 7, a tank inner pressure sensor 7a is disposed to detect a tank inner pressure. An ECU 20 calculates a feedback correction amount based on an oxygen content in exhaust, and executes air-fuel ratio feedback control by using the feedback correction amount. Also, the ECU 20 inhibits the updating of an air-fuel ratio learning value based on the tank inner pressure detected by the tank inner pressure sensor 7a and when the tank inner pressure exceeds a specified determination value.
|
