Abstract: A method for operating an engine with a fuel reformer is presented. In one embodiment a method for operating an engine by injecting a gaseous fuel and a liquid fuel to at least an engine cylinder is presented. The mixture of an engine cylinder may be diluted with EGR and a fraction of gaseous fuel may be increased relative to a fraction of liquid fuel injected to a cylinder in response to an operator tip-out.

Abstract: In one example, a system for a vehicle travelling on a surface is described. The system includes an engine with a cylinder. The cylinder includes a fuel injector that is supplied with gaseous fuel and liquid fuel by a fuel delivery system. The fuel injector is mounted in the vehicle such that the fuel injector inlet faces at least partially toward the road surface. The orientation of the fuel injector enables a quick transition from liquid fuel to gaseous fuel because the gaseous fuel can rise to the injectors and be preferentially injected. Further, various approaches are described from transitioning operation between gaseous and liquid fuel injection.

Abstract: A control device for an internal combustion engine includes an engine and a control unit. The engine can switch fuel to be used among plural kinds of fuel. The control unit delays a timing of switching the fuel to a timing of around a fuel cut in a case where switching the fuel is requested.

Abstract: A homogenizing fuel system involves at least one circulation loop existing outside of the injection system for continuously circulating and maintaining the homogeneity of a multi-fuel mixture apart from any demands by or delivery to the engine's injection system (whether a direct injection fuel gallery or a common rail), and at least one infusion tube configured within the at least one circulation loop for providing a volumetric expansion wherein the fuel mixture is able to slow and more sufficiently mix and thereby become relatively more homogeneous.

Abstract: A fuel delivery system for an internal combustion engine and a method of operating the fuel delivery system is described. As one example, the method includes delivering a first fuel blend from a first fuel tank to the engine; delivering a second fuel blend from a second fuel tank to the engine, the proportion of said second fuel blend delivered to the engine to said first fuel blend delivered to the engine being related to the desired engine output; transferring said first fuel blend from said first fuel tank to said second fuel tank to prevent an amount of said first fuel blend and said second fuel blend in said second fuel tank from falling below a predetermined level; and boosting air delivered to the engine, the amount of boosting being related to latent heat of vaporization of said second fuel blend delivered to the engine.

Abstract: Fuel management system for efficient operation of a spark ignition gasoline engine. Injectors inject an anti-knock agent such as ethanol directly into a cylinder of the engine. A fuel management microprocessor system controls injection of the anti-knock agent so as to control knock and minimize that amount of the anti-knock agent that is used in a drive cycle. It is preferred that the anti-knock agent is ethanol. The use of ethanol can be further minimized by injection in a non-uniform manner within a cylinder. The ethanol injection suppresses knock so that higher compression ratio and/or engine downsizing from increased turbocharging or supercharging can be used to increase the efficiency of the engine.

Abstract: Dual fuel compression ignition engines and methods that allow compression ignition on gaseous fuels like compressed natural gas, hydrogen and ammonia, yet will run on liquid fuels, including diesel fuels for such purposes as starting or when the gaseous fuel is not available or has been consumed and greater range or operating time is needed. Ignition of fuels having a high self ignition temperature is assured by recirculating high temperature exhaust gas back into the intake charge before compression. Existing engines may be converted to run as a dual fuel engine by replacement of the engine head or heads. Various embodiments are disclosed.

Abstract: An open or closed loop EFI system integrating an alcohol sensor is provided on a genset engine. The EFI system provides acceptable engine performance and efficiency when using fuels or fuel blends over a wide band and when starting from a cold state, i.e., starting the engine after the engine has not run for a relatively long period of time. The alcohol sensor enables acceptable operation while the genset engine is cold. The alcohol sensor sends data to the electronic control unit (ECU) and this data, as well as data provided by other sensors that may be available such as an air flow sensor, is used to determine the optimal air-to-fuel ratio (AFR). The ECU actuates the fuel injector which sends the correct amount of atomized fuel to mix with the air flow to be combusted. The fuel mixture, at the requested AFR, enables the engine to start and operate efficiently from a cold state even if the fuel blend has been changed from a previous operation of the engine.

Abstract: Disclosed is a method and corresponding fuel injector for injecting gaseous and liquid fuel into an engine. The method comprises delivering a liquid fuel to a fuel injector, delivering a pressurized gaseous fuel to the fuel injector, entraining the liquid fuel within the gaseous fuel within a chamber of the fuel injector and injecting the gaseous fuel and atomized liquid fuel into the combustion chamber. The liquid fuel can be passed through and dispensed from a needle into a chamber in the injector nozzle where it is entrained in the gaseous fuel during an injection event. The liquid/gas mass ratio is controlled by the needle movement, hydraulic resistances or electronic valves so that the majority of the liquid is injected during the first part of the gas injection. The injector can be used for late cycle direct injection of natural gas, or any number of gaseous fuel blends combined with many liquid fuels such as diesel, biodiesel and DME.

Abstract: Fuel management system for enhanced operation of a spark ignition gasoline engine. Injectors inject an anti-knock agent such as ethanol directly into a cylinder. It is preferred that the direct injection occur after the inlet valve is closed. It is also preferred that stoichiometric operation with a three way catalyst be used to minimize emissions. In addition, it is also preferred that the anti-knock agents have a heat of vaporization per unit of combustion energy that is at least three times that of gasoline.

Abstract: A microprocessor controlled automated, multi-fuel apparatus to blend hydrogen, bio-fuel and/or natural or propane gases. This novel multi-stage apparatus first converts cooking oils into bio-fuel. The system automatically blends the bio-fuel with at least one of or both hydrogen gas, generated by a self-contained on-board hydrogen electrolyzer, and/or natural or propane gases. This blended “Hyenrich” gaseous fuel drives various processes including, but not limited to, cogeneration systems and electrical generators to produce “green” electricity by utilizing an adaptive and predictive learning algorithms to significantly reduce cost per kilowatt and lessen dependency on the over taxed utility grid, while simultaneously reducing emissions of CO, CO2 and NOx, making the method and apparatus an environmentally-friendly energy device.

Abstract: In an internal combustion engine control device having an air-fuel ratio control device that controls the fuel injection amount so that the air-fuel ratio of exhaust gas of an internal combustion engine approaches a target stoichiometric air-fuel ratio, the control device further includes a device that calculates the lower calorific value of fuel, and a device that sets the target stoichiometric air-fuel ratio from the calculated lower calorific value based on a known relationship between the lower calorific value and the stoichiometric air-fuel ratio. It becomes possible to perform the air-fuel ratio control according to the fuel property by utilizing the relationship between the calorific value and the stoichiometric air-fuel ratio.

Abstract: Fuel management system for efficient operation of a spark ignition gasoline engine. Injectors inject an anti-knock agent such as ethanol directly into a cylinder of the engine. A fuel management microprocessor system controls injection of the anti-knock agent so as to control knock and minimize that amount of the anti-knock agent that is used in a drive cycle. It is preferred that the anti-knock agent is ethanol. The use of ethanol can be further minimized by injection in a non-uniform manner within a cylinder. The ethanol injection suppresses knock so that higher compression ratio and/or engine downsizing from increased turbocharging or supercharging can be used to increase the efficiency of the engine.

Abstract: A control system of an internal combustion engine enabling effect production of hydrogen and reliable promotion of burning of ammonia by a simple structure. The internal combustion engine uses ammonia as a fuel and is provided with a fuel injector injecting fuel into an intake passage and a variable operating mechanism able to change a valve opening operation of the intake valve. In the exhaust stroke, this temporarily opens the intake valve. Ammonia for hydrogen production is injected from a fuel injector into the gas flowing back at this time from the combustion chamber to the inside of the intake passage. As a result, hydrogen is produced from the ammonia. In the following intake stroke, this hydrogen is fed into the combustion chamber together with the ammonia and is burned together with the engine drive use ammonia.

Abstract: Various example approaches are described, one of which includes a method for controlling injection of gaseous and liquid fuel to a cylinder during engine starting. Specifically, gaseous fuel is injected during or before an intake stroke of the cycle to form a well-mixed overall lean air-fuel mixture, and then liquid fuel is directly injected to the cylinder at least during one of a compression and expansion stroke of the engine cycle to form a rich air-fuel cloud near the spark plug, where a spark initiates combustion of the injected fuels. In one example, the rich cloud enables additional spark retard, and thus faster catalyst light-off, while maintain acceptable combustion stability of the gaseous fuel.

Abstract: A fuel system for an engine of a vehicle and a method of operating the fuel system are described. As a non-limiting example, the fuel system is controlled in response to engine operating conditions.

Abstract: Apparatus for controlling dual fuel supply to a fuel injected engine having an electronic engine management system (1) that supplies a primary injector control signal (8) to each of primary fuel injectors (2), the apparatus comprising an emulator (11) that emulates the electrical characteristics of a primary injector, a fuel control switch (10) that switches the primary injector control signal (8) from the primary injector (2) to the emulator (11) when an alternative mode is selected, a monitor (16) that monitors the primary injector control signal (8) to produce a monitor signal, and a controller (4) that processes the monitor signal to derive an alternative control signal which is used to control the primary fuel supply or a mixture of the primary fuel and a secondary fuel such as LPG, to the engine. Preferably the primary fuel supply is modulated by controlling injector control pulses. A secondary fuel may also be injected (3) and controlled by the controller (4).

Abstract: Systems, methods, and computer readable storage media are described in which exhaust gas is routed to a hydrocarbon retaining device during starting, and purged to the engine intake manifold. Various alternative approaches are described for controlling operation and diagnosing degradation. Further, various interrelated configurations are described.

Abstract: A system having an internal combustion engine connected to a driven device includes primary and secondary fuel supplies. A primary fuel supply sensor is configured to provide a primary fuel supply signal indicative of a rate of supply of a primary fuel to the engine through the primary fuel supply. A secondary fuel supply sensor is configured to provide a secondary fuel supply signal indicative of a rate of supply of a secondary fuel to the engine through the secondary fuel supply. A power output sensor measures a parameter indicative of a power output of the driven device and provides a power output signal. An electronic controller receives the primary and secondary fuel supply signals and the power output signal, and determines a characteristic of the secondary fuel based on the primary and secondary fuel supply signals and the power output signal.

Abstract: A hybrid vehicle propulsion system and method of operation have been provided. As one example, the system comprises an internal combustion engine including at least a combustion chamber configured to propel the vehicle via at least a drive wheel, a motor configured to propel the vehicle via at least a drive wheel, an energy storage device configured to store energy that is usable by the motor to propel the vehicle, a fuel system configured to deliver gasoline and alcohol to the combustion chamber in varying relative amounts, a control system configured to operate the motor to propel the vehicle and to vary the relative amounts of the gasoline and alcohol provided to the combustion chamber in response to an output of the motor.

Abstract: A gaseous-fuelled internal combustion engine and a method of engine operation improve combustion stability and reducing emissions of NOx, PM, and unburned hydrocarbons. The method comprises fuelling an internal combustion engine with hydrogen and natural gas, which can be directly injected into the combustion chamber together or introduced separately. Of the total gaseous fuel delivered to the engine, at least 5% by volume at standard temperature and pressure is hydrogen. For at least one engine operating condition, the ratio of fuel rail pressure to peak in-cylinder pressure is at least 1.5:1. A fuel injection valve introduces the gaseous fuel mixture directly into the combustion chamber. Two separate fuel injection valves could also introduce the methane and hydrogen separately. An electronic controller controls timing for operating the fuel injection valve(s). The engine has a preferred compression ratio of at least 14:1.

Abstract: An internal combustion engine control apparatus controls an internal combustion engine including: an exhaust passage including branch portions provided for the left and right banks and a common portion in which an exhaust gas purification device is provided; and a fuel supply system that supplies fuel to the respective engine cylinders. In the internal combustion engine, in order to recover the exhaust gas purification device, a bank control is executed in which the air-fuel ratio of the cylinders of the left bank is made rich while the air-fuel ratio of the cylinders of the right bank is made lean. The internal combustion engine is capable of running on alcohol-containing fuel and has an alcohol concentration sensor. The amount of unburned fuel to be supplied to the exhaust gas purification device during the bank control is adjusted based on the alcohol concentration in fuel.

Abstract: Fuel management system for efficient operation of a spark ignition gasoline engine. Injectors inject an anti-knock agent such as ethanol directly into a cylinder of the engine. A fuel management microprocessor system controls injection of the anti-knock agent so as to control knock and minimize that amount of the anti-knock agent that is used in a drive cycle. It is preferred that the anti-knock agent is ethanol. The use of ethanol can be further minimized by injection in a non-uniform manner within a cylinder. The ethanol injection suppresses knock so that higher compression ratio and/or engine downsizing from increased turbocharging or supercharging can be used to increase the efficiency of the engine.

Abstract: The present disclosure teaches a method to extend the distance interval between refueling for gaseous fueled tractor trailers. Recognizing the current dearth of a national gaseous refueling infrastructure to support long distance gaseous powered vehicle transport this disclosure provides a method and system of storing gaseous fuel in high pressure vessels on a tractor and on a trailer and operating an engine for the tractor (and trailer combination) with gaseous fuel feed from both tractor and trailer gaseous fuel supplies.

Abstract: Methods and apparatus are provided for detecting an anomaly in fuel demand data and fuel supply data generated by a fuel metering system for an engine, The method comprises collecting the fuel demand data and the fuel supply data during operation of the fuel metering system, generating expected fuel supply data based on the collected fuel demand data and a nominal response model describing the expected behavior of the fuel metering system, and detecting the anomaly if a difference between the expected fuel supply data and the collected fuel supply data exceeds a predetermined threshold.

Abstract: Fuel is evacuated from a fuel rail by directing liquid fuel from the fuel rail to a fuel tank and then by directing gaseous fuel from the fuel rail to a fuel vapor canister.

Abstract: Methods are provided for operating an engine with a variable fuel blend in a cylinder, where the variable fuel blend varies a peak achievable engine torque for a given operating condition. One example method comprises selectively operating an engine actuator that affects engine torque and engine fuel economy at the given operating condition, and extending operation of the actuator to higher engine torques as a peak engine torque for the given operating condition increases.

Abstract: An improved high viscosity fuel injection pressure reduction system and method is disclosed for use in an internal combustion engine. The system may include a first fuel line and a second fuel line. The first fuel line may be configured to be coupled upstream of a combustion chamber of the engine when the engine is operated with the first fuel and to provide a first pressurized volume when installed. Likewise, the second fuel line may be configured to be coupled upstream of the combustion chamber of the engine when the engine is operated with the second fuel and to provide a second pressurized volume when installed. The first and second volumes of the fuel lines may provide peak injection pressures lower than a desired pressure when the engine is operated with the first and second fuels, respectively.

Abstract: A method is disclosed for making a transition from fueling an engine with hydrogen to another fuel. That other fuel may be gasoline, a gasoline and alcohol mixture, or gaseous fuels, as examples. The other fuel has the capability of providing higher BMEP than the hydrogen because of better air utilization and because the other fuel occupies less volume of the combustion chamber. Because a desirable equivalence ratio to burn hydrogen is at 0.5 or less and a desirable equivalence ratio to burn other fuel is at 1.0, when a demand for BMEP that leads to a transition change from hydrogen fuel to the other fuel, the amount of air supplied to the engine is decreased to provide more torque and vice versa. During a transition in which liquid fuel supply is initiated, it may be desirable to continue to provide some hydrogen, not leaner than 0.1 hydrogen equivalence ratio.

Abstract: An engine system in which hydrogen is employed as a fuel, including a reactor configured to cause a reaction using a catalyst, in which the reactor is constituted by alternately disposing plural exhaust passages and plural fuel passageways of the engine system with a wall interposed therebetween; at least one carrier configured to carry the catalyst and to be formed in a substantially rectangular plate shape is fitted in at least one of fuel passageways; and the carrier is provided with a plate portion which has a surface disposed in a fuel flowing direction and is formed in a substantially rectangular plate shape and at least one slit portion which divides the surface of the plate portion in the fuel flowing direction.

Abstract: An object of the present invention is to avoid an air-fuel ratio difference between cylinders upon recovery from a cylinder deactivation in a situation where some of a plurality of cylinders of an internal combustion engine capable of using a plurality of types of fuels having different properties are to be deactivated upon the halt of fuel injection from an injector. To accomplish the object, a control device to which the present invention is applied includes a fuel property sensor that is installed in a fuel line between a fuel tank and a delivery pipe, and detects a fuel property change from a change in a signal of the fuel property sensor. Upon detection of a fuel property change, the control device prohibits the deactivation of a cylinder before the completion of a fuel property change in the delivery pipe.

Abstract: A method of operation of an internal combustion engine including an intake valve coupled to a combustion chamber, and a port fuel injector positioned upstream of the intake valve in an intake manifold including a throttle, the port fuel injector fluidly coupled to a fuel rail included in a fuel delivery system housing a fuel at least partially composed of alcohol. The method including, during a start-up operation when the temperature of the engine is below a threshold value and fuel is actively being injected into the intake manifold, adjusting a cone angle of a fuel spray from the port fuel injector, via adjustment of the throttle and/or fuel delivery system, based on the position of the intake valve.

Abstract: The invention provides methods of providing fuel to an internal combustion engine, fuel systems for an internal combustion engine and a fuel injector for an internal combustion engine. Ammonia may be heated and pressurized to a selected condition and may used as fuel which is supplemented with hydrogen to assist with ignition, flame propagation, and/or combustion speed.

Abstract: A system and a method of facilitating fuel vaporization in a directly injected internal combustion engine are provided. As one example, the method comprises: closing an exhaust valve of the cylinder; opening an intake valve after the exhaust valve has closed; moving a piston of the cylinder away from top dead center between the closing of the exhaust valve and the opening of the intake valve to expand the cylinder volume and reduce a pressure within the cylinder to below a pressure of an air intake manifold of the cylinder; and initiating an injection of fuel directly into the cylinder via an in-cylinder injector after the exhaust valve has closed.

Abstract: A fuel supply control apparatus for an engine includes an alcohol concentration detector and an engine temperature detector. The apparatus increases an amount of fuel supplied to the engine as the detected alcohol concentration becomes higher. The apparatus increases the amount of fuel as the engine temperature becomes lower and as the alcohol concentration becomes higher. The apparatus feed-back corrects the amount of fuel by using a correction value such that an actual air-fuel ratio becomes a theoretical air fuel ratio. The apparatus determines that water is mixed with fuel when the correction value during a cold operational state indicates leaner than the lean value of the correction value used during a warm operational state. The apparatus reduces the increased amount of fuel when water is mixed with fuel.

Abstract: A system and method for improving emissions of an engine capable of combusting a multi-component fuel comprised of two or more fuels is presented. According to the method, the passage exhaust gases are processed in said exhaust system is determined in part from the concentration of one component fuel.

Abstract: Liquid ammonia is fed from an ammonia storage tank to a vaporizer where it is vaporized. Gaseous ammonia vaporized inside the vaporizer is on the one hand injected from an ammonia injector and on the other hand reformed by a reformer, then injected from a reformed gas injector. The amount of liquid ammonia fed into the vaporizer is made to become equal to the amount of ammonia fed into the combustion chamber in the form of gaseous fuel by control of the amount of feed of the liquid ammonia to the vaporizer.

Abstract: Various systems and methods are described for controlling a dual-fuel engine that has an evaporated gas providing device for providing an evaporated gas into the engine and is operable with hydrocarbon fuel or non-hydrocarbon fuel, alternatively. One example method comprises operating the engine with one of the fuels on the basis of a driver's request, and in response to a determination of a cold engine operation, operating the engine with the non-hydrocarbon fuel for a specified period irrespective of the driver's request. If it is determined that an evaporated fuel is to be provided to the engine while the engine is operating with non-hydrocarbon fuel due the cold engine operation, then switching to operation with hydrocarbon fuel and thereafter providing evaporated fuel into the engine.

Abstract: An engine ECU executes a program including detecting, when refueling with an alcohol fuel is performed, a refueling amount of the alcohol fuel based on a signal transmitted from a sender gauge, increasing DI ratio r that is a ratio between a fuel injection amount from an in-cylinder injector and a fuel injection amount from an intake passage injector, according to the refueling amount of the alcohol fuel, such that the ratio of the fuel injection amount from the in-cylinder injector is higher, and retarding the ignition timing according to the refueling amount of the alcohol fuel.

Abstract: A method for operating an engine with a fuel reformer is presented. In one embodiment a method for operating an engine by injecting a gaseous fuel and a liquid fuel to at least an engine cylinder is presented. The mixture of an engine cylinder may be diluted with EGR and a fraction of gaseous fuel may be increased relative to a fraction of liquid fuel injected to a cylinder in response to an operator tip-out.

Abstract: Fuel management system for efficient operation of a spark ignition gasoline engine. Injectors inject an anti-knock agent such as ethanol directly into a cylinder of the engine. A fuel management microprocessor system controls injection of the anti-knock agent so as to control knock and minimize that amount of the anti-knock agent that is used in a drive cycle. It is preferred that the anti-knock agent is ethanol. The use of ethanol can be further minimized by injection in a non-uniform manner within a cylinder. The ethanol injection suppresses knock so that higher compression ratio and/or engine downsizing from increased turbocharging or supercharging can be used to increase the efficiency of the engine.

Abstract: A system for supply of LPG/methane, ammonia, or gas for supply of petrol or diesel engines, which can be connectable to the electronic control unit (8) provided on board the vehicle, the system being equipped with a gas tank (1); a valve (2), a line (3) for delivery of the gas, a rail (6) for supply of the gas to the engine, a pressure and temperature sensor (7); injectors for the petrol (10), and injectors for the gas (11), is characterized in that, to carry out a continuous variation of the pressure of the gas supplied to the injectors (11), it further comprises an electronic pressure regulator and heat exchanger (5) with injector (4), as well as a control unit for deviation and regulation of the pressure (9), which, during operation of the engine with LPG/methane or ammonia or gas, is designed to receive from the electronic control unit of the engine (8) electrical signals as a function of the injection times, the engine r.p.m.

Abstract: Methods and systems for separating fuel and supplying the separated fuel to an engine are disclosed. In one example, alcohol is separated from a blend of alcohol and gasoline. The methods and systems may improve fuel separator operation by adjusting separator operation in response to engine operating conditions.

Abstract: The present invention provides apparatus for varying an engine's combustion spark timing for use of hybrid fuels, such as bio-fuel and gasoline. An operator selectable switch enables or disables an on-board computer selecting between gasoline and bio-fuel mixtures as the on-board fuel so that engine mounted sensors provide data used to determine optimum fuel-ignition spark discharge values from a computerized table.

Abstract: Provided is a mixer including a ring-shaped swirl chamber; an inlet port which is connected to the swirl chamber in a direction tangential to the outer circumference of the swirl chamber to suck a fuel; a cylindrical vortex chamber coaxially and more inwardly formed with respect to the swirl chamber; a passage which connects the swirl chamber to the vortex chamber; and a taper port which is coaxially connected to the vortex chamber and is configured so that the inner diameter thereof is decreased from the vortex chamber-side end toward the opposite side end; and a supply port which is in communication with the taper port to suck a desired fluid.

Abstract: A dual fuel common rail system includes first and second common rails fluidly connected to a fuel injector by a co-axial quill assembly. Distillate diesel fuel at a first pressure moves from the first common rail through a first fuel passage defined by a quill, through an inner tube and into the fuel injector. Liquid natural gas a second lower pressure moves from the second common rail through a second fuel passage defined by the quill, through a space between the outer tube and the inner tube, and finally into the fuel injector. The quill is partially positioned in a block. First and second compression load adjusters are threadably attached to the block to adjust a compression load on the inner tube and outer tube to inhibit leakage of fuel from the tubes.

Abstract: The present invention refers to a method of using lean fuel-air mixtures at all operating regimes of a spark ignition engine, which is provided with an intake port fuel injection system, wherein said method is characterized in that in order to achieve the efficient lean mixture combustion process, an HHO oxy-hydric gas direct injection should be at a minimum pressure of 10 bar, during compression stroke, after intake valve closing, so that the hydrogen/fuel mixture volumetric fractions value is within the range of about 15% to 25%.

Abstract: An arrangement includes, but is not limited to an internal combustion engine, a pressure reducer that reduces gas pressure of gaseous fuel for the engine. The reducer connects on a high-pressure side to a gas tank and connects on the low-pressure side to a controllable gas injection valve regulating the gas flow. A high-pressure shutoff valve is on the high-pressure side and connected to the reducer to shut-off the gas flow from the gas tank. The high-pressure shutoff valve includes, but is not limited to a pilot valve with a small opening and a main valve with a large opening, and an electronic controller used at least for controlling the high-pressure valve and a gas injection valve. The pilot valve of the high-pressure valve opens in chronological order before the gas injection valve.

Abstract: Fuel management system for efficient operation of a spark ignition gasoline engine. Injectors inject an anti-knock agent such as ethanol directly into a cylinder of the engine. A fuel management microprocessor system controls injection of the anti-knock agent so as to control knock and minimize that amount of the anti-knock agent that is used in a drive cycle. It is preferred that the anti-knock agent is ethanol. The use of ethanol can be further minimized by injection in a non-uniform manner within a cylinder. The ethanol injection suppresses knock so that higher compression ratio and/or engine downsizing from increased turbocharging or supercharging can be used to increase the efficiency of the engine.

Abstract: Various systems and methods are described for controlling fuel injection of a dual fuel engine which includes first and second fuel rails and first and second fuel pumps. In one example, while pumping is suspended in the second fuel rail, the first fuel is injected to all but one cylinder of the engine and the second fuel is injected to the one cylinder in a predetermined sequence. As such, the fuel injector injecting to the one cylinder is isolated and its performance may be assessed without significantly affecting engine performance.