Abstract: A device that enables gasoline internal combustion engines to efficiently use fuel with higher ethanol content. The device measures various data such as ethanol content, RPM, temperature, intake air pressure, mass airflow, exhaust gas, crank sensor, among other data, to determine to an ideal enrichment pulse duration to apply to the fuel injector.

Abstract: A device that enables gasoline internal combustion engines to efficiently use fuel with higher ethanol content. The device measures various data such as ethanol content, RPM, temperature, intake air pressure, mass airflow, exhaust gas, crank sensor, among other data, to determine to an ideal enrichment pulse duration to apply to the fuel injector.

Abstract: A method is described for operating an electric fuel pump constituting a low-pressure pump in a fuel supply system for an internal combustion engine, having a high-pressure reservoir and a high-pressure pump, of a motor vehicle. The electric fuel pump is operated at least temporarily, during a time period during which the internal combustion engine is switched off during operation of the motor vehicle, with a minimum value for a control application variable for the electric fuel pump.

Abstract: A method for ascertaining a viscosity of a fuel with the aid of an electric fuel pump which is integrated into a fuel circuit including an overflow valve which includes a permanently open discharge channel, a fuel supply and delivery being adjusted with the aid of the electric fuel pump in the fuel circuit at a specific pressure and the viscosity of the fuel being ascertained by taking into account a delivery rate of the electric fuel pump.

Abstract: Systems and methods for automatically determining system specifications for one or more HVAC components are provided. In one embodiment, a GUI is generated by a processor and presented to a user. The processor may request information relating to a building where one or more HVAC components are to be installed. The user may provide one or more identifiers through the GUI. The processor may use the one or more identifiers to access a database and automatically determine at least one characteristic associated with the building. The processor may use the determined characteristic to determine one or more system specifications for the HVAC components. The processor may use the GUI to display the determined system specifications for the one or more HVAC components.

Abstract: An injection control apparatus includes an injector for injecting fuel which is accumulated under pressure toward a combustion chamber, an injector driver for supplying a current to an electromagnetic actuator used for a solenoid valve, and a state detection unit for detecting a state of an engine or an ambient environment. A valve opening control unit supplies a first current to the electromagnetic actuator for opening the solenoid valve. An opened-state maintaining control unit supplies a second current to the electromagnetic actuator for maintaining the solenoid valve continuously in an opened position. A timing control unit variably adjusts a period of time from a starting time of the valve opening control unit to a time when the opened-state maintaining control unit becomes active in place of the valve opening control unit, in accordance with a result of detection provided by the state detection unit.

Abstract: A fuel injection device for an internal combustion engine includes: a high/low pressure fuel system configured to inject fuel into cylinders 12a to 12d through an in-cylinder injector 44; and a low pressure fuel injection system configured to inject fuel into an intake manifold 14 through an intake path injector 46. An ECU 60 incorporates: an idling stop/start unit 68 that stops the engine when an idling stop condition is satisfied, and restarts the engine when the idling stop condition is no longer satisfied; and a fuel injection control unit 70 that causes, after the idling stop condition is no longer satisfied, fuel remaining in the first fuel injection unit to be injected into the cylinder, before rotation of a crank shaft 32 starts, so that the engine 10 is automatically restarted, and causes fuel injection to be started from the second fuel injection unit when predetermined condition is satisfied.

Abstract: The gas filling system includes: a vehicle that includes a tank and a first communication instrument; and a gas station that includes a second communication instrument. The vehicle includes: a first temperature sensor that acquires temperature information of the gas stored in the tank; a second temperature sensor that acquires temperature information outside the tank; and a controller. The controller permits transmission of the temperature information of the first temperature sensor to the second communication instrument on the condition that the absolute value of a difference between an indicated value of the first temperature sensor and an indicated value of the second temperature sensor is smaller than or equal to a predetermined value, and prohibits transmission of the temperature information of the first temperature sensor to the second communication instrument on the condition that the absolute value of the difference is larger than the predetermined value.

Abstract: A fuel delivery system for an engine is provided. The fuel delivery system includes a tank, a temperature sensor, a delivery conduit, a return conduit, a heat exchanger, a first valve, a second valve, an accumulator, and a controller. The controller is configured to receive a signal indicative of a temperature of a fuel present within the tank. The controller is also configured to control at least one of the first valve and the second valve to selectively bypass at least a portion of the fuel to the tank through the return conduit and the accumulator based, at least in part, on the received signal. The portion of the fuel is adapted to raise the temperature of the fuel present within the tank.

Abstract: The invention relates to a pump system comprising a positive-displacement pump module, preferably a screw pump, a drive module which can be exchanged separately from the positive-displacement pump module, said drive module comprises an electric drive motor and a frequency converter associated therewith for controlling or adjusting a drive motor speed, control means comprising a controller for producing an adjustment variable (Ys) for the frequency converter in accordance with a reference variable (W) and a first actual operational parameter (X) and logistic means associated with the controller, and reference variable defining means for providing the reference variable (W) for the control means. According to the invention, the control means are provided in a control module separately from the drive module, and the drive module can be exchanged separately from the control module, and the drive module does not have a designed and/or controlled controller for producing the adjustment variable (Ys).

Abstract: This disclosure provides system and method that can determine hydraulic start of injection (SOI) in engines using an in-cylinder pressure sensor. The system and method determine apparent heat release rate (AHRR) curve data for the cylinder from the pressure information provided by the in-cylinder pressure sensors, and the hydraulic SOI from the derivative of the AHRR curve data. The system and method provide diagnostic, control and/or compensation opportunities for fuel injector operation in high pressure fuel rail engine systems without use of expensive or complex fuel injector components.

Abstract: A device for controlling the speed of an internal combustion engine comprising a control lever movably associated to a support element, which may be the engine casing or a portion thereof. The control lever is moveable at least between a first position, in which the engine is at a first rotation regime, and a second position, in which the engine is at a second rotation time. A selective locking mechanism is provided that prohibits the control lever from being stably positioned at any (and all) intermediate positions between the first and second positions. In one embodiment, a biasing force generated by the device automatically forces the control lever into one of the first or second positions when the control lever is located in any of the intermediate positions and an actuation force is ceased.

Abstract: In a method for controlling an internal combustion engine, during a standard operating mode a specified first fuel quantity is injected by actuating a first fuel injector during a first actuation period and by an accompanying opening of a first valve needle, and a specified second fuel quantity is injected by actuating a second fuel injector during a second actuation period and by an accompanying opening of a second valve needle, and (i) during a first calibration operating mode, a calibration actuation of the first fuel injector is performed while an actuation of the second fuel injector is carried out, or (ii) during a second calibration operating mode, a calibration actuation of the second fuel injector is carried out while an actuation of the first fuel injector is carried out.

Abstract: A torque requesting module generates a first torque request for a spark ignition engine based on driver input. A torque conversion module converts the first torque request into a second torque request. A setpoint module generates setpoints for the spark ignition engine based on the second torque request. A model predictive control (MPC) module: identifies sets of possible target values based on the setpoints; generates predicted parameters based on a model of the spark ignition engine and the sets of possible target values, respectively; selects one of the sets of possible target values based on the predicted parameters; and sets target values based on the possible target values of the selected one of the sets. A first constraint module selectively sets a predetermined range for first one of the target values. The MPC module limits the first one of the target values to within the predetermined range.

Abstract: A method for diagnosing a performance issue in a vehicle system having a diesel engine, a fuel system, and an on-board diagnostic system. The method includes cranking the engine, and, if a pressure sensed in the fuel system during or after the engine cranking differs by a threshold amount from the pressure sensed during a previous operation of the engine, indicating excessive fuel viscosity in the on-board diagnostic system.

Abstract: A fuel injection device is equipped with a fuel injection valve that is mounted in an engine body and injects fuel containing air bubbles, and void fraction adjustment means that changes a void fraction of the fuel that is to be injected from the fuel injection valve. The void ratio adjustment means increases the fuel pressure of the fuel to be injected from the fuel injection valve when an increase of the void fraction is requested. The void fraction adjustment means adjusts the void fraction of the fuel by changing temperature of the fuel to be injected from the fuel injection valve. By appropriately controlling the void fraction, both fuel atomization and securement of the net amount of fuel can be achieved.

Abstract: A system and method for controlling the viscosity of liquid fuel delivered from a fuel tank to the fuel injectors of an internal combustion engine. A viscosity sensor is placed in the fuel line, or in a bypass fuel line, in close proximity downstream the fuel injectors. A heat exchanger is placed on the fuel line downstream the sensor. The sensor is a rotating cylinder having a nominal rotation velocity, and is configured to rotate such that the nominal rotation velocity increases or decreases in response to fuel viscosity. The sensor delivers a measurement signal to a control unit, which performs a closed loop algorithm to adjust the heat provided by the heat exchanger until the measured rotation matches a target rotation.

Abstract: An oxygen concentration sensor is disposed in an engine exhaust passageway. The alcohol concentration in the fuel used in the internal combustion engine is detected. A target impedance is set on the basis of the detected alcohol concentration. The actual impedance of a sensor element of the oxygen concentration sensor is detected. The heater output of the exhaust gas sensor is controlled so that the actual impedance becomes equal to the target impedance, whereby the temperature of the sensor element represented by the impedance becomes equal to a target temperature represented by the target impedance.

Abstract: A reservoir structure of a fuel suction unit or pump module for a diesel vehicle is provided. The reservoir structure includes a reservoir 10 having a bottom surface 14. A primary opening 12 is provided in the bottom surface for permitting fuel to pass from a fuel tank of the vehicle into the reservoir. A secondary opening 16 is provided in the reservoir 10 that is elevated from the bottom surface 14. A valve member 18 is associated with the secondary opening 16. The valve member 18 is constructed and arranged to close the secondary opening under certain pressure conditions in the reservoir and, under pressure conditions in the reservoir different from the certain pressure conditions, to permit fuel to enter the reservoir through the secondary opening in the event the primary opening is substantially blocked.

Abstract: In a method to determine the temperature of a fuel in a common rail injection system of an engine, the fuel temperature at one place of the common rail injection system is calculated from a fuel temperature at another place of the common rail injection system.

Abstract: A method adjusts fuel injection to account for fuel puddling in the engine intake. The fuel is adjusted based on the ethanol content of the fuel in the puddle, and the make-up of the various fuel components in the puddle. In this way, it is possible to better account for the effects of these parameters on puddle evaporation.

Abstract: A method adjusts fuel injection to account for fuel puddling in the engine intake. The fuel is adjusted based on the ethanol content of the fuel in the puddle, and the make-up of the various fuel components in the puddle. In this way, it is possible to better account for the effects of these parameters on puddle evaporation.

Abstract: A diesel cycle internal combustion engine can be operated with a variety of fuels having different boiling points and different viscosity-temperature characteristic curves, with a fuel circuit that includes a fuel tank, a fuel pump, a fuel line, at least one fuel filter, a high-pressure pump, an injection system device and a return line to return fuel to the fuel tank, where a control valve is provided in the return line for dividing or diverting the fuel flow to the fuel tank and/or to the fuel filter, and where the fuel division or diversion is undertaken as a function of the viscosity of the fuel in use such that the fuel filter will thence be heated to a temperature based on heat transfer from the fuel in use, and further where a pressure relief valve is provided between the fuel filter and the high-pressure pump.

Abstract: A fuel injection system for an internal combustion engine has a lubricity improver supply for adding a lubricity improver to low-viscosity fuel supplied to a fuel injection apparatus of the engine. A controller controls the lubricity improver supply so that the amount of the lubricity improver added to fuel at the inlet to the fuel injection apparatus is increased as engine rotation speed, engine load, or injection pressure is increased. With the system, wear or sticking of the plunger can be prevented even when low-viscosity fuel is used by improving lubrication conditions to secure necessary lubrication condition for the sliding part in accordance with engine operation conditions, fuel temperature and viscosity.

Abstract: A control system used with an engine determines a fuel injection timing according to a detected engine operating condition and fuel injection is executed through a fuel injection valve. The target ignition timings of the fuel are set according to the detected engine operating condition and stored in a memory. An ignition delay of the actual ignition timing relative to the target ignition timing and a cetane number of the fuel are calculated. Control values of the recirculation amount of exhaust gases are set according to the detected engine operating condition and stored in the memory. The stored control value is retrieved and the recirculation amount of exhaust gases is controlled using the retrieved control value. A correction amount of the recirculation amount of exhaust gases is calculated according to the estimated cetane number and the recirculation amount of exhaust gases is controlled using the corrected control value.

Abstract: The Inventor invented a combustion control device which optimizes combustion regardless of the cetane number of a fuel of an internal combustion engine (1) by focusing on the correlation between the cetane number and specific gravity of the fuel, and correcting combustion control based on the specific gravity of the fuel. The combustion control device comprises a sensor (7, 32, 36, 37) which detects the specific gravity of the fuel, a device which adjusts a combustion-related element of the internal combustion engine (1) such as fuel injection, compression end in-cylinder temperature and an intake air swirl (15, 19, 27, 51), and a controller (21) programmed to correct a target value of the element based on the specific gravity of the fuel (S414, S424, S430), and control the adjusting device so that the corrected target value is realized (S415, S425, S430).

Abstract: A combustion control system of an internal combustion engine is comprised of a specific gravity detecting section which detects a specific gravity of fuel used in the engine, and a combustion control section which controls combustion in the engine on the basis of the specific gravity.

Abstract: A fuel injection system includes a fuel pressure boost pump having a pump body that defines a pump cylinder and a pump chamber. A piston structure is movable in the pump cylinder along a longitudinal axis of the piston structure. A fuel inlet conduit and a fuel outlet conduit are in flow connection with the pump chamber, the fuel inlet conduit being provided with a first one-way valve and the fuel outlet conduit being provided with a second one-way valve. A temperature sensor is in thermally conductive contact with the pump body.

Abstract: A system for estimating an auxiliary-injected fuel quantity includes a fuel injector for injecting fuel into an engine, a fuel pump supplying fuel to a fuel collection unit that then supplies fuel to the fuel injector, and a control circuit that generates an auxiliary-injected fuel quantity estimation model by disabling the fuel pump prior to fuel injection, and enabling the fuel pump to resume fuel pumping following fuel injection, by the fuel injector, determines a first pressure in the fuel collection unit after stabilization of the fuel pressure therein following disablement of the fuel pump and prior to the fuel injection, determines a second pressure in the fuel collection unit after the fuel injection and prior to resuming pumping of fuel by the fuel pump, and forms the model as a function of the first and second pressures and an injector on-time for a number of different engine operating conditions.

Abstract: A system and method of controlling a fuel injector is provided. A first injection signal is applied to a hydraulically actuated fuel injector to inject a quantity of fuel into a combustion chamber of an internal combustion engine. An amount of an operating fluid used by the fuel injector to inject the quantity of fuel into the combustion chamber is calculated. The amount of fuel injected into the combustion chamber is estimated based on the amount of operating fluid used by the fuel injector. A viscosity parameter is determined for the fuel injector based on the duration of the first injection signal and the estimated amount of fuel injected into the combustion chamber.

Abstract: A system and method of controlling a fuel injector is provided. A first injection signal is applied to a hydraulically actuated fuel injector to inject a quantity of fuel into a combustion chamber of an internal combustion engine. An amount of an operating fluid used by the fuel injector to inject the quantity of fuel into the combustion chamber is calculated. The amount of fuel injected into the combustion chamber is estimated based on the amount of operating fluid used by the fuel injector. A viscosity parameter is determined for the fuel injector based on the duration of the first injection signal and the estimated amount of fuel injected into the combustion chamber.

Abstract: The present invention provides a method and apparatus for determining the oil grade of an actuating fluid in a fuel system. The method includes the steps of determining an actuating fluid temperature, a pump speed, and a peak pressure or a timing event of the actuating fluid, and responsively determining the oil grade of the actuating fluid.

Abstract: The present invention provides a fuel injection system and method of operating the fuel injection system. The fuel injection system includes at least one hydraulically actuated fuel injector fluidly connected with a source of high pressure actuation fluid. A viscosity sensor determines the viscosity of the hydraulically actuated fuel injector. A controller in communication with the fuel injector and the viscosity sensor is configured to determine the rate of change of the viscosity of the high pressure hydraulic actuation fluid. The supply of high pressure actuated fluid to the fuel injector is based, at least in part, on the rate of change of the determined viscosity of the high pressure actuation fluid.

Abstract: A temperature distribution of fuel flowing through a delivery pipe is detected by two fuel temperature sensors provided in the delivery pipe and a fuel tank. When this temperature distribution exceeds an allowable range, adjusted pressure pumping processing in which an amount of fuel corresponding to an injection amount is pumped is stopped and quantitative pressure pumping processing is begun. In quantitative pressure pumping, a rate of fuel flowing through the delivery pipe is increased to an amount exceeding an amount of fuel injected from injectors. With this feature, an amount of fuel flowing through the delivery pipe is greatly increased, a temperature rise rate due to thermal energy from the engine is lowered, and the range of temperature distribution of fuel is narrowed down as a whole. Therefore, differences in output torque among the cylinders is reduced, and variations in the revolution of the engine are suppressed or prevented.

Abstract: A fuel injection apparatus for a diesel engine has a fuel injection pump for feeding fuel under pressure and fuel injection nozzles provided in the engine to inject fuel fed from the injection pump. A pressure sensor for detecting fuel pressure is provided in a midway in a fuel line connecting the injection pump to the injection nozzles. An electronic control unit (ECU) computes the frequency of the fuel pressure based on a detected value from the pressure sensor immediately after fuel is injected from the injection nozzles. The ECU then computes a fuel bulk modulus based on the result of the computation of the frequency of the fuel pressure. Based on the computed bulk modulus, the ECU computes a fuel injection start and end time. Further, the ECU adjusts an instruction value for fuel injection control based on the result of the computation of injection start and end, and controls the injection pump based on the adjusted instruction value.

Abstract: An apparatus and method for varying the current levels of a fuel injection signal used in connection with an electronically controlled hydraulic actuator unit injector fuel system is disclosed. The apparatus and method varies the current level of the fuel injection signal delivered to the unit injector based on sensed engine parameters, which preferably include a sensed pressure of hydraulic actuating fluid and a sensed temperature of the engine.

Abstract: In an accumulator type fuel injection control device, a feed hole (28) provides communication between a common rail (24) for storing fuel from a fuel pressure pump (29) and a fuel injection valve (11); a control oil passage (23a, 23b, 23c) extends from the feed hole (28) to an oil chamber (19); a three-way electromagnetic valve (23) exerts the pressure of a fuel oil on the oil chamber (19) to close a needle valve (15), and discharges the fuel oil in the oil chamber (19) to a fuel return passage (51) to open the needle valve (15); fuel oil pressure correcting means (103) corrects a fuel oil pressure P.sub.0 on the basis of a fuel oil temperature t.sub.F detected by fuel oil temperature detecting means (44); and simultaneously, fuel injection volume correcting means (108) corrects a fuel injection volume Q.sub.0 ; whereby the temperature of fuel flowing to a fuel return system is suppressed to prevent damage to members used in the fuel return system.

Abstract: An apparatus and method for varying the duration of current levels of a fuel injection signal used in connection with an electronically controlled hydraulic actuator unit injector fuel system is disclosed. The apparatus and method varies the duration of the pull-in current of the fuel injection signal delivered to the unit injector based on sensed engine parameters, which preferably include a sensed temperature of the engine and engine speed.

Abstract: In an electronically controlled hydraulic actuation type fuel injection device, a viscosity value (mu) of hydraulic oil is detected by an oil viscosity detection sensor and then an aimed base valve opening time T.sub.injBASE during which a solenoid valve of a unit injector to be kept open is corrected based on the detected viscosity value. Lubricating oil for lubricating an engine is used as the hydraulic oil. The oil viscosity detection sensor includes an oil pump for supplying the lubricating oil to each sliding part of the engine and an oil sensor for detecting a delivery pressure Po of the oil pump. All of the sliding parts of the engine is regarded as one "throttle" and the viscosity (mu) of the hydraulic oil is determined according to a pre-prepared map from the engine speed Ne and the delivery pressure Po, utilizing change in passage resistance at the "throttle" caused by oil viscosity change.

Abstract: This invention includes selecting a desired pressure for fuel injection in an internal combustion engine. The selection improves control of fuel injection by keeping the fuel in the fuel rail in a liquid state and by keeping the fuel injectors in an operating region where fuel injector fuel flow is less sensitive to changes in fuel injector pulse width.

Abstract: An electronically-controlled heavy fuel oil injection system comprises a pumping chamber for pressurizing fuel and a direct-operated check for controlling fuel injection. A control fluid different from the fuel is used to operate regulating apparatus for controlling the fuel injection pressure and fuel injection timing. The regulating apparatus are isolated from the high viscosity, heavy fuel oil. Pressurization of fuel begins before the start of fuel injection. Fuel injection is initiated by exposing one end of the check to low pressure control fluid while the other end is exposed to high pressure fuel. Fuel injection is terminated by exposing the one check end to high pressure control fluid to hydraulically balance the check and allow a biasing device to close the check.

Abstract: In a diesel engine comprising a fuel injection pump which supplies pressurized fuel by a plunger to a fuel injection nozzle, fuel properties such as fuel viscosity are determined. A fuel supply start timing by the plunger and fuel injection start timing by the fuel injection nozzle are respectively detected, a difference between them is computed as an injection retardation period, and the fuel viscosity is determined based on the injection retardation period. A fuel injection amount, injection timing or exhaust recirculation amount are corrected based on the determined fuel viscosity, therefore errors in their control do not arise due to differences of fuel viscosity.

Abstract: In one aspect of the present invention, a method for correcting an engine map for use in an electronic control system that regulates the quantity of fuel that a hydraulically-actuated injector dispenses into an engine. The engine map stores a plurality of engine operating curves. The method modifies at least one of the engine operating curves in response to the engine temperature, which is indicative of the temperature of the actuating fluid used to hydraulically actuate the injector. Consequently, the engine map curves are corrected to compensate for changing engine temperatures to insure that the hydraulically-actuated fuel injectors dispense a desired quantity of fuel.

Abstract: A fuel delivery system for an internal combustion engine that includes a fuel pump responsive to application of electrical power for delivering fuel under pressure to the engine. A pressure sensor supplies a pressure signal as a function of fuel pump output pressure. Electrical circuitry is responsive to the pressure signal for applying electrical power to the pump. A temperature sensor is operatively coupled to the circuitry for automatically varying the pump power signal to increase fuel pump output pressure when temperature at the temperature sensor exceeds preselected threshold temperature.

Abstract: In one aspect of the present invention, a method is disclosed that controls the actuating fluid pressure supplied to a hydraulically-actuated injector and the time duration over which the hydraulically-actuated injector injects fuel. The desired actuating fluid pressure and injection duration is swept across a range of values to achieve an optimum combination of values to start an engine.

Abstract: An apparatus and method for detecting the viscosity of actuating fluid used to actuate a hydraulically-actuated electronically-controlled injector is disclosed. In an internal combustion engine system including an engine having a crankshaft, a crankshaft angular speed sensor responsive to rotation of the crankshaft, a voltage sensor, and an engine coolant temperature sensor, which respectively generate angular speed, voltage, and temperature indicative signals, are provided. An electronic control module is provided with a memory means, the control module having an associated viscosity indicative signal or parameter whose magnitude is representative of the actuating fluid viscosity and is a function of the angular speed, and voltage indicative signals.

Abstract: A viscosity sensitive, pressure divider arrangement for use as part of an engine timing control tappet system where that system includes a block oil pressure supply, hydromechanical control valve and an oil sump, the pressure divider arrangement including an inlet chamber, a divider chamber and an exit chamber. The inlet chamber is connected to the divider chamber by means of a first connecting conduit having a relatively short length. The outlet side of the divider chamber is connected with the exit chamber by means of a second connecting conduit which has a length substantially longer than the length of the first connecting conduit. Additionally, the divider chamber includes a pressure-assist outlet aperture which is in flow communication with the hydromechanical control valve. The viscosity of oil flowing into the pressure divider arrangement will be acted upon by the combination of connecting conduits wherein the first connecting conduit is less viscosity sensitive than is the second connecting conduit.

Abstract: An apparatus for controlling fuel injection parameters for fuel injection quantity, injection timing, and actuating fluid pressure of a hydraulically-actuated electronically-controlled fuel system. The apparatus utilizes signals indicative of actuating fluid pressure (P.sub.f) and/or actuating fluid viscosity (v) in order to determine such parameters.

Abstract: In a hydraulically-actuated electronically-controlled unit injector, the viscosity of the actuating fluid used to actuate the unit injector varies with ambient temperature and affects the magnitude of pressure drops in the actuating fluid circuit. Such variations in viscosity affect the magnitude of the fuel delivery command pulsewidth and/or actuating fluid pressure required for engine startup versus that required for normal engine operation. The present invention provides an improved hydraulically-actuated electronically-controlled unit injector and methods of operation which compensate for variations in the viscosity of the actuating fluid used to hydraulically actuate a piston. The stroke of the piston is controlled electronically and/or mechanically in order to achieve an appropriate amount of fuel injection.

Abstract: Methods of starting a hydraulically-actuated electronically-controlled fuel injection system are disclosed. One method comprises the steps of pressurizing actuating fluid used to actuate a unit injector and actuating an electrical actuator assembly of the unit injector to cause fuel injection only when the pressure of the actuating fluid is at least equal to a selected minimum level. This method of the present invention ensures that the unit injector does not diminish the pressure of the actuating fluid until the pressure has reached a selected minimum level required to effect fuel injection. This method allows the pumping capacity of the high pressure actuating fluid pump to be minimized while ensuring quick starting of an engine by the fuel system.