A method for deposit mitigation in a gaseous fuel injector that introduces a gaseous fuel through a gaseous fuel orifice directly into a combustion chamber of an internal combustion engine includes at least one of a) reducing the ago length of the gaseous fuel orifice by substantially between 10% to 50% of a previous length of a previous gaseous fuel orifice showing deposit accumulation above a predetermined threshold; b) providing the gaseous fuel orifice with an inwardly and substantially linearly tapering profile; c) determining deposit mitigation is needed; and performing at least one of the following deposit mitigation techniques i) increasing gaseous fuel injection pressure wherein deposit accumulation is reduced during fuel injection; and ii) decreasing gaseous fuel temperature wherein a rate of deposit accumulation is reduced; and d) injecting compressed air through the gaseous fuel orifice during shutdown of the internal combustion engine; whereby torque loss in the internal combustion engine due to deposit accumulation in the gaseous fuel orifice is reduced below a predetermined value.

A pneumatic and hydraulic testing and cleaning kit for gasoline type fuel injectors used in electronic fuel injection systems on most cars today. The tester/cleaner apparatus includes a stand with pneumatic quick disconnect for applying air and a solvent in pulses at 35 to 55 psi to clean dirty fuel injectors.

An internal-combustion engine includes: a direct fuel injector directly injecting fuel into a combustion chamber; and a control device. The control device performs: presumption processing that presumes, based on an operating condition of the internal-combustion engine, that a thermoplastic deposit is formed on an injection hole portion of the direct fuel injector; temperature control processing that increases a temperature of the injection hole portion when the thermoplastic deposit is presumed to be formed; and first removal processing that injects the fuel from the direct fuel injector after the temperature control processing.

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.

Fuel nozzle assemblies are flushed after ultrasonic cleaning. In one embodiment, a method includes: cleaning a fuel nozzle assembly by ultrasonic cleaning; and after the ultrasonic cleaning, flushing the fuel nozzle assembly using a solution, the fuel nozzle assembly comprising a valve located in an interior of the fuel nozzle assembly, the solution flowing through the interior of the fuel nozzle assembly, and the flowing of the solution controlled by the valve.

A fluid injection system includes a fluid injector assembly, a fluid conditioning module having an outlet port that is fluidly coupled to an inlet port of the fluid injector assembly via an injector assembly inlet conduit. The fluid injection system further includes a flush conduit fluidly coupled to the outlet port of the fluid conditioning module, a flush valve disposed in the flush conduit and configured to control a flowrate of fluid therethrough, and a controller operatively coupled to the fluid conditioning module and the flush valve, the controller being configured to adjust a flowrate of a fluid through the injector assembly inlet conduit by controlling a flowrate of fluid through the flush conduit.

Systems and methods provide for cleaning the air intake valves and surrounding areas of an engine. A gravity-fed cleaning-fluid dispenser may feed cleaning fluid into a hose through a metered device that meters a rate at which the cleaning fluid flows into the hose. A second fluid meter connected to a distal end of the hose further meters the rate at which a mixture of the cleaning fluid and air from is dispersed into the running GDI engine. Cleaning fluid may be distributed to the engine at a gradually decreasing rate as a volume of cleaning fluid in the dispenser decreases as the service progresses.

In a method of cleaning injectors of a direct-injection controlled-ignition engine, while idling, maximum fuel pressure to be injected for cleaning is calculated, by executing for at least one predetermined engine operating speed an iterative loop. During each loop the injected fuel pressure value increases and the injection time corresponding to the increased pressure is determined, selecting for each operating speed a cleaning pressure equal either to the maximum fuel pressure to which an injection time greater than the calibrated minimum injection time determined for the operating speed corresponds or to a maximum limit pressure corresponding to a given calibrated pressure for the engine/injectors system. Secondly, a cleaning treatment includes selecting an operating speed allowing the maximum cleaning pressure and controlling an engine operation by applying this speed and programming the cleaning pressure over a treatment duration exceeding the operating time allowed while running under operating conditions of this kind.

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.

Fuel nozzle assemblies are flushed after ultrasonic cleaning. In one embodiment, a method includes: cleaning a fuel nozzle assembly by ultrasonic cleaning; and after the ultrasonic cleaning, flushing the fuel nozzle assembly using a solution, the fuel nozzle assembly comprising a valve located in an interior of the fuel nozzle assembly, the solution flowing through the interior of the fuel nozzle assembly, and the flowing of the solution controlled by the valve.