Abstract: In a lean-burn engine equipped, in the exhaust pipe, with NOx trap catalyst that collects NOx by absorption or occlusion, the rich spike start timing and rich spike volume are optimized. The above subject is achieved by an engine control system equipped, in the downstream side of the NOx trap catalyst, with a NOx sensor that detects the NOx component in the exhaust, NOx trap catalyst model, and a device that controls the engine operating condition based on the outputs of the NOx trap catalyst model and NOx sensor.

Abstract: To offer a fuel supply system and fuel supply method for direct injection engine that realizes higher output. In a fuel supply system for direct injection engine of the present invention, equipped with a primary fuel injector that injects fuel directly into the cylinder of the direct injection engine and supercharger that increase the intake air quantity of the engine, a secondary fuel injector is installed in addition to the primary fuel injector. In a specified engine load area, fuel is supplied using the primary fuel injector and secondary fuel injector. Even though the fuel quantity injected from the primary fuel injector into the cylinder is limited, the fuel supply system for direct injection engine constructed as above can increase the engine output because the fuel insufficiency can be supplied by the secondary fuel injector.

Abstract: In a lean-burn engine equipped, in the exhaust pipe, with NOx trap catalyst that collects NOx by absorption or occlusion, the rich spike start timing and rich spike volume are optimized.

Abstract: A high-pressure fuel pump accelerates a rise in fuel pressure from engine start-up to shorten an engine start-up time, reduce an exhaust gas substance and improve or increase an engine output. The high-pressure fuel pump is part of a control device which controls an in-cylinder injection engine having a fuel injection valve, a high-pressure fuel pump, and a crank angle sensor. The high-pressure fuel pump is provided with a plunger for pressurizing the fuel placed in the high-pressure fuel pump, a pump drive cam, and a cam angle sensor. A drive signal setting device outputs drive signals to the high-pressure fuel pump at least two or more times from the time of crank angle sensor signal detection to the determination time of the crank and cam angle sensor phases.

Abstract: A high-pressure fuel pump control device and an in-cylinder injection engine control device are provided in which a high-pressure fuel pump accelerates a rise in fuel pressure from the start-up of an engine thereby to make it possible to shorten an engine start-up time, reduce an exhaust gas substance and improve or increase an engine output, for example. The high-pressure fuel pump control device and in-cylinder injection engine control device control an in-cylinder injection engine having a fuel injection valve provided in a cylinder, a high-pressure fuel pump for force-feeding a fuel to the fuel injection valve, and a crank angle sensor for detecting the position of a crankshaft of the cylinder. The high-pressure fuel pump is provided with a plunger for pressurizing the fuel placed in the high-pressure fuel pump, a pump drive cam for driving the plunger, and a cam angle sensor for detecting the position of the pump drive camp.