Abstract: A method for controlling fuel injection of a direct injection fuel system, the fuel system having a fuel pump, the method comprising: variably operating the fuel pump to maintain a fuel pressure at a selected pressure, temporarily increasing pump operation to increase pressure sufficiently above said selected pressure and then reducing pump operation; during at least a fuel injection subsequent to the reduction in pump operation, correlating pressure decrease to injector operation, and adjusting fuel injection operation based on the correlation.

Abstract: An engine system and a method of starting an internal combustion engine of the engine system are described. In one embodiment, the method includes adjusting a fuel pressure within a fuel rail to a first value; after the fuel pressure within the fuel rail attains the first value, initiating delivery of fuel to the internal combustion engine from the fuel rail by successively injecting fuel directly into combustion chambers of the internal combustion engine; and after at least a first fuel injection event, reducing the fuel pressure within the fuel rail from the first value to a second value over subsequent successive fuel injection events by adjusting an operating parameter of the high pressure fuel pump. The method may optionally include increasing an air-fuel ratio over subsequent successive fuel injection events after fuel delivery is initiated by varying an amount of fuel that is directly injected into the combustion chambers.

Abstract: A method for controlling fuel injection timing of at least one fuel injector in a direct injection fuel delivery system of an internal combustion engine during a mode of engine operation where a plurality of fuel injection events are performed by the at least one fuel injector during a cylinder event is provide. The method includes, during a first fuel injector needle bounce condition following the end of injection of a first fuel injection event, sending a start of injection signal for a second fuel injection event at a first time, and during a second fuel injector needle bounce condition following the end of injection of the first fuel injection that differs from the first fuel injector needle bounce condition, sending the start of injection signal for the second fuel injection event at a second time that is earlier than the first time.

Abstract: A method for starting an internal combustion engine, the method comprising identifying cylinder stroke during the engine start responsive to a fuel rail pressure.

Abstract: A method for controlling fuel injection of a direct injection fuel system, the fuel system having a fuel pump, the method comprising: variably operating the fuel pump to maintain a fuel pressure at a selected pressure, temporarily increasing pump operation to increase pressure sufficiently above said selected pressure and then reducing pump operation; during at least a fuel injection subsequent to the reduction in pump operation, correlating pressure decrease to injector operation, and adjusting fuel injection operation based on the correlation.

Abstract: A control system 32 and method for controlling neutral idle operation of a vehicle 10 is provided. The method includes measuring a brake pressure in a brake control line of vehicle 10. The control line communicates fluid to a brake 128 coupled to a wheel of vehicle 10. The method further includes determining an incline angle of vehicle 10. The method further includes determining a desired brake pressure based on the incline angle. The desired brake pressure is a pressure sufficient to allow the vehicle brakes to maintain vehicle 10 at a predetermined position. Finally, the method includes disengaging a transmission clutch 46 torsionally coupling a vehicle engine 12 to a wheel 24 when the measured brake pressure is greater than the desired brake pressure to initiate neutral idle operation.