Abstract: Operating an engine system includes cold starting an engine, closing spill valves to pressurize fuel in a plurality of plunger cavities, opening injection valves in some of a plurality of fuel injectors to inject fuel into firing cylinders in an engine cycle, and opening spill valves in some of the plurality of fuel injectors while injection valves therein remain closed to bleed fuel to a lower pressure space in the engine cycle. The pressurization of fuel in the fuel injectors remaining closed parasitically loads the engine to increase a fuel burned amount hastening warm up and limiting misfire. Related apparatus and control logic is also disclosed.

Abstract: An electronically controlled fuel injector includes an injection valve; a control valve fluidly connected between a pressurized fuel supply passage and a control chamber for controlling operation of the injection valve, the control valve movable between a non-injection position and an injection position; the injection valve configured to inject fuel with the control valve in the injection position; and a control member chamber including an orifice that fluidly connects the control member chamber with a low pressure return line of a fuel supply system. The control chamber is fluidly coupled with a pressure communication passage such that the control chamber is fluidly coupled with the low pressure return line through the orifice in the control member chamber when the control valve is in the injection position. The pressure communication passage includes a two-way, variable flow rate valve.

Abstract: An electronically controlled fuel injector includes an injection valve; a control valve fluidly connected between a pressurized fuel supply passage and a control chamber for controlling operation of the injection valve, the control valve movable between a non-injection position and an injection position; the injection valve configured to inject fuel with the control valve in the injection position; and a control member chamber including an orifice that fluidly connects the control member chamber with a low pressure return line of a fuel supply system. The control chamber is fluidly coupled with a pressure communication passage such that the control chamber is fluidly coupled with the low pressure return line through the orifice in the control member chamber when the control valve is in the injection position. The pressure communication passage includes a two-way, variable flow rate valve.

Abstract: A fuel system for an internal combustion engine includes an actuation train having a cam follower, a pushrod, a rocker arm, and a camshaft having a cam lobe rotatable in contact with the cam follower according to an ascending ramp phasing, a peak phasing, and a descending ramp phasing. The fuel system further includes a fuel injector including an electrically actuated spill valve. A fueling control unit is in communication with the spill valve and structured to close the spill valve during the ascending ramp phasing, such that a plunger cavity pressure is increased to oppose a plunger-advancement inertia of the actuation train. Related methodology and control logic is also disclosed.

Abstract: A fuel system is disclosed for use with an engine. The fuel system may have a common rail, a first type of fuel injector fluidly connected to the common rail, and a second type of fuel injector fluidly connected to the common rail. The second type of fuel injector may include a pumping portion having a bore formed therein, and a plunger reciprocatingly disposed in the bore. The second type of fuel injector may also include an accumulator portion fluidly connected to the common rail and configured to receive fuel pushed from the bore of the pumping portion by the plunger, a nozzle portion, and a valve portion fluidly connecting the pumping, nozzle, and accumulator portions.

Abstract: A fuel system is disclosed for use with an engine, including a fuel injector assembly fluidly coupled with a low-pressure fuel conduit, an accumulator, and a cap within an opening in the accumulator. The fuel injector assembly may be structured to draw in low-pressure fuel, pressurize the fuel, and store the pressurized fuel in the accumulator for injection to a combustion chamber. The cap has a pressure sensor and a pressure relief valve therein, and drains fuel leaked past fluid seals between the cap and each of the pressure sensor, the pressure relief valve, and the accumulator by way of a common drain line.

Abstract: A fuel injector assembly for an engine system includes a fuel pressurization mechanism, a fuel injector, and a flow-directing sleeve positioned about the fuel injector and including sealing surfaces for sealing with a cylinder head and with an injector body. Slots are formed at least in part in the sealing surfaces to direct fuel from the cylinder head into an incoming cooling passage extending to the fuel pressurization mechanism, and from an outgoing cooling fuel passage into the cylinder head.

Abstract: A fuel system is disclosed for use with an engine. The fuel system may have a common rail, a first type of fuel injector fluidly connected to the common rail, and a second type of fuel injector fluidly connected to the common rail. The second type of fuel injector may include a pumping portion having a bore formed therein, and a plunger reciprocatingly disposed in the bore. The second type of fuel injector may also include an accumulator portion fluidly connected to the common rail and configured to receive fuel pushed from the bore of the pumping portion by the plunger, a nozzle portion, and a valve portion fluidly connecting the pumping, nozzle, and accumulator portions.

Abstract: A fuel system is disclosed for use with an engine, including a fuel injector assembly fluidly coupled with a low-pressure fuel conduit, an accumulator, and a cap within an opening in the accumulator. The fuel injector assembly may be structured to draw in low-pressure fuel, pressurize the fuel, and store the pressurized fuel in the accumulator for injection to a combustion chamber. The cap has a pressure sensor and a pressure relief valve therein, and drains fuel leaked past fluid seals between the cap and each of the pressure sensor, the pressure relief valve, and the accumulator by way of a common drain line.