To provide a fuel supply control device capable of maintaining an excellent exhaust characteristic over a long period by properly correcting a fuel supply quantity by taking into consideration the degradation of an exhaust recirculation mechanism.
An average value KO2WTEGR at EGR performing time and an average value KO2WOEGR at EGR stopping time of an air-fuel ratio correction factor KO2 are calculated (S102), and when the difference DKO2 is larger than a prescribed value DKO2EGRF, it is judged that the exhaust gas refluxing mechanism is degraded, and a degradation correction factor KEGRFLOW is calculated according to an intake pressure variation quantity DPBEGR for indicating a degradation degree (S104 to S106). The degradation correction factor KEGRFLOW is used to calculate the fuel supply quantity, and is set so as to increase the fuel supply quantity as the degradation degree becomes large.
NIKI MANABU
TSUTSUMI KOJIRO
IWAMOTO TAKASHI
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