Abstract: A system and method cleans a fuel pump pressure control function valve having (i) an orifice linking a first region (e.g., a high pressure region) and a second region (e.g., a low pressure region) and (ii) a closing member biased to close the orifice when fuel pressure in the first region is below a threshold pressure. Cleaning the valve may include increasing the pressure in the first region to an overpressure condition, thereby causing the closing member to be moved to open the orifice such that a rapid flow of fuel occurs from the first region to the second region. A pressure control function valve can therefore be conveniently cleaned without requiring engine disassembly or adding additional physical elements. The fuel pump pressure control function valve may be part of safety or check valve of a fuel pump.

Abstract: A system and method cleans a fuel pump pressure control function valve having (i) an orifice linking a first region (e.g., a high pressure region) and a second region (e.g., a low pressure region) and (ii) a closing member biased to close the orifice when fuel pressure in the first region is below a threshold pressure. Cleaning the valve may include increasing the pressure in the first region to an overpressure condition, thereby causing the closing member to be moved to open the orifice such that a rapid flow of fuel occurs from the first region to the second region. A pressure control function valve can therefore be conveniently cleaned without requiring engine disassembly or adding additional physical elements. The fuel pump pressure control function valve may be part of safety or check valve of a fuel pump.

Abstract: A method of managing a number of active cylinders of an engine can be provided. The method comprises: determining for a current engine operating condition a number of active cylinders required for the current engine operating condition; if the determined number of active cylinders is different than a current number of active cylinders, selecting one or more cylinder which is to be activated or deactivated in order to provide the determined number of active cylinders; where one or more cylinders is to be activated, retarding ignition timing for a cylinder preceding in firing order the first firing of a first activated cylinder; and where one or more cylinders is to be deactivated, advancing ignition timing for a cylinder that is not to be deactivated and which precedes in firing order a first cylinder which is to be deactivated.

Abstract: An engine control system is provided for an internal combustion system having variable valve timing operated by at least one variable valve actuator. The engine control system is operable to calculate fuel injection amounts based on predicted volumetric efficiency and to delay a control signal for initiation of the variable valve actuator by a control delay timing. An embodiment can provide compensation for fuel amounts injected despite rapid variable valve actuation.