A hybrid electric vehicle has been developed using the Peugeot XUS-11ATE diesel engine to drive an auxiliary power unit. This engine has a mechanical distributor type fuel pump and indirect fuel injection. It is proposed to convert the engine to a full-authority digital fuel injection system by replacing the original fuel injectors and fuel pump and adding an electronic control unit and an EGR valve. Reduction of exhaust smoke requires an early end of injection of fuel and reduction of NOx, unburned HC, and CO emissions requires retarded start of injection. Therefore, to reduce both smoke and NOx, while maintaining a low BSFC, the fuel injection duration must be short with a high rate of injection. The proposed system with digital electronic control meets both of these requirements and precisely time the injection to minimize exhaust emissions.
