Patent attributes
An engine control system includes an EGR device 10 which connects an exhaust passage Ex and an intake passage I and has an EGR valve; an intake throttle valve 41 placed in the intake passage I; and an engine control unit which is provided with an engine operation data calculator A1 accumulating mileages of a vehicle or an engine operation period, a fuel injection controller A2 controlling a fuel injection amount and a fuel injection timing, an EGR controller A3 controlling an opening of the EGR valve; a throttle valve controller A4 controlling an opening of the intake throttle valve; and an EGR passage cleaning controller A5 which delays a fuel injection timing Tn, increases an opening β g of the EGR valve, and reduces an opening θ s of the intake throttle valve when the total mileage or the total operation period calculated by the engine operation data calculator becomes equal to a predetermined threshold.
