Cleaning, maintaining, refurbishing, and/or diagnosing engine components including fuel system components, e.g., such as fuel-injectors. In one embodiment, a method of cleaning a fuel system component is provided. The method includes supplying a cleaning solution through the fuel system component, discontinuing the supplying of the cleaning solution, repeating the supplying of the cleaning solution and the discontinuing of the supplying of the cleaning solution a plurality of times, decoupling the source of cleaning solution, and connecting a source of fuel to the fuel system component, and supplying fuel through the fuel system component to re-establish fuel-based operation. In additional embodiments, a method of processing a fuel system component while it remains connected to an engine assembly, and a method of diagnosing a defective fuel system component, are provided.

In a method of removing particles in an injector of a diesel engine, a stop of the diesel engine may be recognized. An injection signal may be inputted into the injector of the stopped diesel engine. A control valve of the injector may be moved in a low-pressure passage by the injection signal to remove the particles accumulated on an inner wall of the low-pressure passage. Thus, a malfunction of the control valve caused by the particles may be previously prevented.

A method and system for cleaning a fuel nozzle during engine operation is provided. Operations include operating the compressor section to provide the flow of oxidizer at a first oxidizer flow condition to the combustion chamber, wherein the first oxidizer flow condition comprises an environmental parameter; operating the fuel system at a first fuel flow condition to produce a fuel-oxidizer ratio at the combustion chamber; comparing the environmental parameter to a first environmental parameter threshold; and transitioning the fuel system to a second fuel flow condition corresponding to a cleaning condition at the fuel nozzle if the environmental parameter is equal to or greater than the first environmental threshold.

The invention relates to a maintenance system for a fuel injection system provided in an internal combustion engine, the fuel injection system defining a hydraulic circuit having a high-pressure pump, a solenoid valve, a pressure sensor, a metering solenoid valve, a common rail and injectors. The maintenance system includes a manual control unit connected to a hydraulic unit, the hydraulic unit being capable of being inserted into the hydraulic circuit of the fuel injection system and including a test solenoid valve and a test pressure sensor mounted in a body provided with an inlet mouth, an outlet mouth and a leakage mouth.

A method and system for cleaning a fuel nozzle during engine operation is provided. Operations include operating the compressor section to provide the flow of oxidizer at a first oxidizer flow condition to the combustion chamber, wherein the first oxidizer flow condition comprises an environmental parameter; operating the fuel system at a first fuel flow condition to produce a fuel-oxidizer ratio at the combustion chamber; comparing the environmental parameter to a first environmental parameter threshold; and transitioning the fuel system to a second fuel flow condition corresponding to a cleaning condition at the fuel nozzle if the environmental parameter is equal to or greater than the first environmental threshold.

The invention relates to a maintenance system for a fuel injection system provided in an internal combustion engine, the fuel injection system defining a hydraulic circuit having a high-pressure pump, a solenoid valve, a pressure sensor, a metering solenoid valve, a common rail and injectors. The maintenance system includes a manual control unit connected to a hydraulic unit, the hydraulic unit being capable of being inserted into the hydraulic circuit of the fuel injection system and including a test solenoid valve and a test pressure sensor mounted in a body provided with an inlet mouth, an outlet mouth and a leakage mouth.

A controller for controlling a fuel injection valve and a fuel pressure adjustment mechanism integrates a deposition amount of deposits per unit time, and estimates a deposition amount of deposits on an injection hole of the fuel injection valve. The controller causes the fuel pressure adjustment mechanism to increase a fuel pressure, when the estimated deposition amount exceeds a predetermined value, and corrects the unit deposition amount acquired by the deposition amount estimation according to the set fuel injection timing of the fuel injection valve. The controller corrects such that as compared with the unit deposition amount when the fuel injection timing is set to a first timing away from a top dead center of the piston by a first period, the unit deposition amount decreases when the fuel injection timing is set to a second timing away by a second period longer than the first period.

A fuel injection apparatus for injecting fuel to an engine having cylinders, includes: injectors corresponding to the cylinders; a regulator for fuel pressure supplied to the injectors; and a processor. The processor performs: deciding to start a deposit removal for removing deposits adhering to injector-nozzles; and controlling each injector to inject fuel in a single injection mode for injecting one time or a divided injection mode for injecting multiple times in one combustion cycle and control the regulator based on engine operation condition. The controlling includes, when controlling each injector to inject fuel in the divided injection mode based on the engine operation condition, sequentially controlling each injector to reduce injection number in one combustion cycle when the deposit removal is decided to be started, and then controlling the regulator to increase fuel pressure.

Ethylene-C.sub.3-C.sub.10 alpha olefin copolymers, dispersants and lubricating oils/fuel compositions incorporating dispersants, and related methods are generally described herein. The copolymer may comprise ethylene-derived units and C.sub.3-C.sub.10 alpha-olefin-derived units. The C.sub.3-C.sub.10 alpha-olefin-derived units may have a carbon number from three to ten. For example, the C.sub.3-C.sub.10 alpha-olefin-derived units may be propylene-derived units. The dispersants may be made from copolymers having low metal and/or fluorine contents.

A fuel injector cleaning system includes an injector cleaning housing that defines a cavity structured to receive a fuel injector. A heater is operatively coupled to the housing. A three-way valve includes a first inlet fluidly coupled to a calibration fluid reservoir, and a second inlet fluidly coupled to a cleaning fluid reservoir. An intake line includes a first end fluidly coupled to an outlet of the valve, and a second end structured to be fluidly coupled to a fuel inlet of the fuel injector. A controller is operatively coupled to each of the heater and the valve. The controller is structured to actuate the valve so as to cause flow of a cleaning fluid to the fuel injector. The heater is operated so as to heat the cleaning fluid. The valve is actuated so as to cause flow of a calibration fluid to the fuel injector.