Abstract: A thermal type air flow meter includes a device for measuring an intake air flow rate by heating and controlling a heating resistor, and an analog-to-digital converter for digitizing an air flow rate signal of the air flow rate measurement device. The air flow rate measurement device inputs a reference voltage to the analog-to-digital converter so that the reference voltage can be converted from an analog signal to a digital signal, and the air flow rate signal can be corrected in accordance with the value of the reference voltage. A/D conversion of the air flow rate signal can be executed accurately even when the voltage of the reference voltage source of the A/D converter in an electrical control unit is fluctuating.

Abstract: A method for determining a gas charge of an internal combustion engine having an intake manifold. The intake manifold has a gas mixture, which is a fresh air/fuel mixture and an exhaust gas, and further has a gas mass flow from the intake manifold and an intake manifold pressure. The method includes the steps of determining a partial pressure of the fresh air/fuel mixture in the gas mass flow by setting up a mass balance for a fresh air/fuel mixture mass flow, determining a partial pressure of the exhaust gas in the gas mass flow by setting up a mass balance for an exhaust gas mass flow, and determining a gas mass flow via a throttle based on a function that depends on a temperature compensation factor, a pressure compensation factor and a factor depending on a ratio of a pressure downstream of the throttle to a pressure upstream of the throttle. The pressure downstream of the throttle corresponds to the intake manifold pressure.

Abstract: The following conditions are used as requirements for executing a fuel property detection: an intake air temperature is lower than a restart judging value; a water temperature is in a predetermined range; and it is in an idle operation. In a case that the requirements are established, an injection amount of fuel and a combustion amount of fuel are calculated. After that, the injection amount is corrected by using a learned value for correcting an error of system, and the combustion amount is corrected according an intake pressure. A fuel property parameter for evaluating the fuel property is calculated based on a ratio of an accumulated value of the combustion amount relative to an accumulated value of the injection amount during a predetermined time. A command value of the injection amount for a fuel injection valve is corrected according to the fuel property parameter calculated above. As a result, the fuel property is reflected in the command value of the injection amount.

Abstract: A common-rail fuel injection system is disclosed, which calculates a mean value of common-rail pressures that remain pulsating after pressure drop due to any fuel injection, and considers the mean value to be a net common-rail pressure after fuel injection thereby finding with accuracy an amount of fuel to be injected. The common-rail pressure kept constant before the beginning of the fuel injection starts pulsating due to a pressure surge or oil hammer resulting from the fuel injection. The mean value is derived from the common-rail pressures sensed over a time interval for data sampling, which starts with the beginning of the command pulse. The mean value may be considered to be an approximation close to the net common-rail pressure that has fallen due to the fuel injection. The amount of fuel injected, as given depending on a net amount of pressure drop from the pressure before any fuel injection to the mean value, may be found accurately irrespective of characteristic deviation every injector.

Abstract: The flow meter is a device having a laser Doppler anemometer (LDA) which measures the instantaneous center line velocity of fluid flow in a pipe and processes the instantaneous velocity so obtained to compute the volumetric flow rate, mass rate, and other flow characteristics as instantaneous quantities and/or integrated over a time interval using an electronic processing method which provides an exact solution to the Navier-Stokes equations for any periodically oscillating flow. The flow meter is particularly adapted for measuring the flow characteristics of high pressure automotive fuel injection systems. Three embodiments of the flow meter are described, including a stationary stand for off-line bench testing flow rate in a fuel injection system, a portable flow meter for inline testing in a vehicle's fuel line, and an on-board flow meter sensor connected to an engine control module.

Abstract: A fuel injector-pressure sensor combination for fuel injection systems for direct injection of fuel into the combustion chamber of an internal combustion engine and for measurement of the pressure in the combustion chamber includes a piezoelectric or magnetostrictive element. The piezoelectric or magnetostrictive element is positively connected with a valve closer which interacts with a valve seat face to form a sealing seat. In addition, an electronic control and analysis circuit is provided which activates the piezoelectric or magnetostrictive element during a fuel injection phase in such a way that the valve closer activated by the piezoelectric or magnetostrictive element lifts off from the valve seat face and opens the seat. During a pressure measurement phase, the control and analysis circuit detects a pressure in the combustion chamber transmitted from the valve closer to the piezoelectric or magnetostrictive element and converted by the latter into an electric signal.

Abstract: Systems and methods for detecting degradation of a sensor in a vacuum brake booster coupled to a manifold of an internal combustion engine include measuring an engine or vehicle operating parameter to detect operating or control conditions and detecting degradation of the sensor based on the engine or vehicle operating parameter. In one embodiment the operating parameter is a measured or estimated manifold pressure. A pressure drop across a check valve disposed between the brake booster and the intake manifold may also be considered.

Abstract: A method of mass-flow determination for an internal combustion engine which comprises developing two terms, one being a function of the air pressure downstream of the throttle and the other being a function of engine speed and throttle opening as determined by appropriate transducers. Specifically the invention recognises that the term which is a function of air pressure is a substantially straight line and, for calibration purposes can be accepted so calibration is effectively done by modifying the other term to provide optimum performance under various conditions. The mass flow determination is a product of the two terms. The invention also provides an internal combustion engine being controlled by the use of the method.

Abstract: A method of adjusting performance of an electronically controlled hydraulic system comprises the initial step of providing at least one electronically controlled hydraulic device having a control valve member operably coupled to an electronic actuator. The control valve member impacts a seat when the device is activated and de-activated. The electronically controlled hydraulic device is then activated according to an activation profile. The seat impacts of the control valve member are detected and recorded. The detected seat impact characteristics are compared to expected seat impact characteristics.

Abstract: A leak detection system for detecting leakage from a portion of a vapor confinement space which is upstream of an inlet of a canister purge valve relative to an engine. During a test, an electric-motor-operated air pump pumps atmospheric air through a flowpath providing communication between the pump and the vapor confinement space. A flowmeter has a thermistor in the flowpath. The thermistor has a predetermined temperature vs. electric current characteristic that enables it to provide a signal correlated to flow of air through the flowpath. An electric circuit supplies and measures the electric current drawn by the thermistor to create a signal representative of the pumped airflow. The test is conducted in accordance with an algorithm that pre-heats the thermistor to a stable state before the pump is turned on. The pump is then turned on to create a predefined superatmospheric target pressure in the vapor confinement space.

Abstract: A thermal type air flow rate sensor is formed with at least a heating resistor and a temperature measuring resistor on a semiconductor substrate via an electric insulation film, by forming the heating resistor and the temperature measuring resistor with an impurity doped silicon (Si) semiconductor thin film, and by performing high concentration doping process so that an electric resistivity (&rgr;) of the silicon (Si) semiconductor thin film is less than or equal to 8×10−4 &OHgr; cm, with simplified fabrication process for formation of the silicon (Si) semiconductor thin film at the same impurity concentration simultaneously in a lump at low cost.

Abstract: A stroke identifying unit, for an electronic fuel injection control system of an engine, can identify cylinder strokes without detection of the rotation of the engine's camshaft. The stroke identifying unit includes a crank pulse generator for detecting a phase of a crankshaft of the engine. In a four cylinder engine, an intake pressure sensor detects the combined intake pressures in the second to fourth intake pipes, communicating with the second to fourth cylinders. A fuel injection control unit identifies strokes of the first to fourth cylinders on the basis of a relationship between the detected phase of the crankshaft and the detected intake pressures.

Abstract: A fuel injection control device expanding the dynamic range for controlling the amount of fuel and preventing the wasteful consumption of electric power. The device comprises fuel pressure regulator means 4 for adjusting the fuel pressure Pf, various sensors 3 inclusive of a fuel pressure sensor, injector drive means 5A for opening the valve body of an injector 2, and injection control means 1A for controlling the fuel pressure regulator means and the injector drive means depending on the operation conditions, wherein the injection control means 1A includes a holding current control unit 16A that variably sets the injector holding current iha depending on the fuel pressure in order to control the valve-opening time by controlling the exciting current ia and the excitation time of the injector, and variably sets the holding current to a minimum required value so that the holding current decreases with a decrease in the fuel pressure.

Abstract: An outboard motor has an induction system and a fuel supply system. The two systems are linked together to improve responsiveness of the fuel supply system based upon fluctuations in pressure within the induction system. The motor includes an induction air pressure detection system. The detection system comprises a pressure sensor and a connection to at least two different air intake pipes of the induction system. The connection between the sensor and the two pipes is configured such that the distance between the sensor and each of the pipes is the same. The detection system is configured to sample the pressure in multiple intake pipes associated with multiple cylinders using connecting conduits that have the same length from each intake pipe to the pressure sensor.

Abstract: A control device for controlling an air-to-fuel ratio when fuel is injected in an internal combustion engine, comprises: a state detecting unit for detecting parameters representing operating states of the internal combustion engine; a counting unit for counting the number of times of explosion in a cylinder just after the engine starts; and a unit for estimating an air-to-fuel ratio just after the engine starts from the operating state parameters and the number of times of explosion.

Abstract: A method for setting the torque in an internal combustion engine determines a set air mass and a corresponding throttle valve setting from a set torque in a control tract. An actual air mass allows the difference between a set air mass and the actual air mass to be determined by comparing a set value and the actual value. The controlling effort for setting a desired torque will be reduced. A correction value for the difference between the actual and set values of the air mass is calculated whereby an adaptation of the control tract to the difference is performed. Thereby, in the control tract, a correspondingly adapted throttle valve position will then be associated with a set torque that is to be established. A compensation of the previously determined difference between the set value and the actual value of the air mass is produced. An actual fuel mass fed to the combustion chambers can be utilized for determining the actual air mass, as can a fuel/air mass ratio of a mixture fed to the combustion chambers.

Abstract: A thermal-type airflow meter comprises an airflow meter body and a measuring part. Both of the frame of a housing which accommodates the electronic circuit, and a sub-passage member which has the heating resistor positioned within a sub-passage, are arranged on a metallic base. Further, the frame, the sub-passage member, the metallic base and the cover are each fixedly attached to at least two respective different members. A connector of the housing, the frame and the sub-passage member are formed in a flat shape to form the measuring module. The measuring module is inserted through an insertion hole to locate the heating resistor within the main air passage, and the fixing flange of the housing is fixedly attached to the airflow meter body.

Abstract: A throttle position system for an internal combustion engine. Included is a method for filtering a throttle position sensor using a maximum allowable rate of change based on factors such as, for example, physical driver limits or physical electronic actuator limits, for rejecting noise spikes. The filtered signal retains the necessary lead for use in air/fuel ratio control while eliminating problems associated with large noise spikes. Fuel is supplied based on the filtered throttle position and measurements from either a mass air flow sensor or a manifold pressure sensor.

Abstract: An internal combustion engine, in particular for a motor vehicle, includes a throttle arranged in an intake pipe, through which air can be fed to a combustion chamber. Furthermore, the internal combustion engine includes a valve arranged in an exhaust gas recirculation line, through which exhaust gas can be fed to the intake pipe. A first mass flow through the throttle can be determined by a control device. Furthermore, a second mass flow through the valve can be determined by the control device. Finally, a third mass flow fed to the combustion chamber can be determined by the control device from the first mass flow through the throttle and the second mass flow through the valve.

Abstract: A fuel injection control apparatus which infers fuel temperature from cooling water temperature and intake air temperature. From these inferred temperatures, a correction coefficient of the air-fuel ratio is found from the inferred fuel temperature and the intake manifold pressure by using data stored in a map. The map is set up so that a characteristic thereof shows that, the higher the inferred temperature of fuel, the larger the correction coefficient of the air-fuel ratio and, thus, the longer the fuel injection time. Subsequently, an ineffective injection time TV is corrected in accordance with the inferred fuel temperature. A fuel injection time TI is then computed from a basic injection time TP, a representative correction coefficient Ftotal representing all correction coefficients including the correction coefficient of the air-fuel ratio, and the ineffective injection time TV.

Abstract: A method of fuel injection comprises an initial step of providing an electronically-controlled hydraulically-actuated fuel injector. An on-time for the fuel injector that corresponds to a desired amount of fuel is determined. The fuel injector is activated for that on-time. Next, the actual amount of fuel injected by the fuel injector is estimated. The actual amount of fuel is compared to the desired amount of fuel. If the actual amount of fuel is substantially more than the desired amount of fuel, the on-time for a subsequent injection event is adjusted.

Abstract: A control method as described, the method being intended for use controlling the operation of a compression ignition internal combustion engine having an accelerometer associated therewith and arranged to sense vibrations of the engine, and a monitor arranged to monitor the output signal of the accelerometer, by monitoring the output signal during a detection time interval and a reference time interval, using the output signal during the reference time interval to compensate for background noise, and using the noise compensated signal in controlling the operation of the engine.

Abstract: A fuel injector having a needle valve and an injector body employs at least one movable needle-guide which having a plurality of movable members disposed between the needle valve assembly and the injector body. The movable members can be insulating members which are substantially entirely composed of insulating material such as ceramics. In applications which do not require electrical isolation, the movable members could be formed of conductive material. The movable members are preferably spherical elements which are partially cradled within an annular trough formed in the needle valve such that the movable members ensure that the needle valve is held in spaced relation to the injector body. While the movable members are preferably formed as solid ceramic spheres, other insulating materials and/or shapes could be utilized.

Abstract: A thermal-type airflow meter comprises an airflow meter body and a measuring part. Both of the frame of a housing which accommodates the electronic circuit, and a sub-passage member which has the heating resistor positioned within a sub-passage, are arranged on a metallic base. Further, the frame, the sub-passage member, the metallic base and the cover are each fixedly attached to at least two respective different members. A connector of the housing, the frame and the sub-passage member are formed in a flat shape to form the measuring module. The measuring module is inserted through an insertion hole to locate the heating resistor within the main air passage, and the fixing flange of the housing is fixedly attached to the airflow meter body.

Abstract: A throttle device comprises a throttle valve having a circular body and a compensation member made of resin. The body has an upstream half rotatable at an upstream side with respect to a throttle shaft and a downstream half rotatable at a downstream side with respect thereto. The compensation member is installed on the upstream half at a downstream side thereof and bulged toward an inner wall of a throttle body. When the throttle valve rotates in an open direction from a closed position, the area of an intake air passage at the upstream half is smaller than the area of a passage at the downstream half and thus, the difference between the flow velocity at the upstream half and that at the downstream half can be reduced. Accordingly, it is possible to restrict the flow of the intake air from becoming oblique to the axis of the intake air passage and hence measure the flow rate of the intake air accurately.

Abstract: Disclosed is a control system and method of a two cycle direct fuel injection engine capable of smoothly suspending combustions in the cylinder during light load operation of the engine. Based on a map parameterizing the engine speed and the target engine load, it is judged whether or not, when the engine load is in the light load condition, the target engine load is located in a suspending area in which misfires tend to occur. If the target engine load is not in the suspending area, since there is no possibility of misfire, the normal combustion cycle continues to operate. On the other hand, if the target engine load enters into the suspending area, the control system instructs the fuel injection and ignition apparatuses so as to suspend fuel injection and spark ignition with a frequency determined according to the magnitude of the engine load. The frequency is determined by a predetermined formula such that it is reduced as the engine load becomes high and is increased as the engine load becomes low.

Abstract: In a process for determining the opening time of an injection valve of a common-rail injection system, an injection duration is derived from a characteristic diagram based on the fuel quantity to be injected and the static pressure in the common rail. For reading in the characteristic diagram, the value of the static pressure in the common rail is corrected by an amount obtained from the compressional vibration of the fuel as a function of its compressibility, the injected fuel quantity during at least one preceding injection operation, and the time between the at least one preceding injection operation and the current injection operation.

Abstract: A fuel injector employs at least one sensing device for sensing material deformations occurring in the injector components during usage to thereby monitor injector performance. The sensing device is preferably at least one of the many piezoelectric sensors available and is advantageously affixed within a cylinder of an injector to detect deformations of the injector cylinder within the needle valve/power piston column of an injector to detect deformations of the column which occurs when the high-pressure fuel in the control chamber is suddenly converted pressure and vice versa. Whereas the sensing devices of the invention can be placed at a variety of locations, they are advantageously arranged to detect material deformations within the injector cylinder or valve/piston column where such deformations are appreciably large during injector usage.

Abstract: The present invention is a fuel injection system having one or more fuel injectors and an electronic control system therefore. The preferred fuel injector has a double magnetic latching solenoid three-way or four-way spool valve that controls the flow of a working fluid that is used to control the discharge of fuel into the combustion chamber or intake manifold of an engine through the nozzle of the injector. The control system provides actuating current pulses to each of the solenoids to actuate and latch the solenoids to effect initiation and termination of the injection. Disclosed are control systems that provide a snap action in one or both actuating directions of the valve by electromagnetically retaining the valve in the latched condition until the force in the actuated solenoid builds to a high level, and then releasing the valve for higher acceleration to the actuated position.

Abstract: The invention is directed to a method for controlling an internal combustion engine of a vehicle utilizing a control unit which detects operating data of the engine. The control unit includes a computing unit for processing the operating data and the control unit drives actuating elements for influencing the operating state of the engine in dependence upon the detected operating data. In the method, the concentration of at least one component of the ambient air is detected with a sensor and the concentration is processed in the control unit. The actuating elements are driven in dependence upon the at least one component of the ambient air. An arrangement for carrying out the method is also disclosed.

Abstract: The present invention provides a method of compensating for changing fuels in a flexible fueled vehicle using a fuel composition sensor. The methodology detects and models an alcohol concentration transition at fuel injector tips following a fuel addition. The methodology improves the accuracy of engine fueling during an alcohol concentration change by delaying the application of a fuel composition multiplier until the fuel analyzed by the fuel composition sensor actually reaches the injectors.

Abstract: A fuel control system and method for an engine having a returnless fuel system uses a fuel blend sensor to adjust a desired air/fuel ratio to allow continuous fuel blend changes. Engine operating conditions are monitored and used to track the movement of small fuel quantities from the fuel blend sensor to the fuel injectors. The system and method use the cells in the stack to represent the volume of the fuel quantities and their corresponding measured fuel blend.

Abstract: A system and method for controlling a vapor recovery system. The system uses a vapor sensor canister containing activated charcoal and two temperature probes. The sensor provides a differential temperature measurement that can be monitored and processed to determine hydrocarbon content in the vapor recovery system.

Abstract: The present invention provides a flexible fuel compensation system for determining the percent alcohol content of fuel in a flexible fueled vehicle at the instance of fueling and in an open loop operating mode. According to the invention, two estimated percent alcohol content values are calculated based on the old fuel mixture's alcohol content and two fueling possibilities. A first value is calculated for the possibility that E85 fuel was added to the tank and a second value is calculated for the possibility that E0 fuel was added to the tank. If the inferred ethanol content increases above a positive threshold during closed loop operation, the system assumes that E85 fuel has been added to the tank. Conversely, if the inferred ethanol content decreases below a negative threshold, the system assumes that E0 fuel was added to the tank.

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: A fuel injection control device for outboard motors optimizes the air-fuel ratio when trim is applied to the outboard motor, especially those with two-cycle engines. In such an outboard motor, engine speed, throttle setting, engine boost pressure, engine temperature, intake air temperature, and/or other variables are detected and a basic fuel injection volume determined. Fuel is supplied to each of the engine's cylinders according to the detected values. A trim angle detecting means is used to indicate trim angle. During low-speed operation, the trim angle is detected, and the magnitude of a change in the trim angle is calculated. The magnitude of the change in the trim angle is used to estimate the residual fuel volume within the engine. The estimated value is used to apply correction to the basic fuel injection volume following the change in the trim angle. As a result, during low-speed operation, an optimal air-to-fuel ratio can be obtained when the trim of the outboard device is changed.

Abstract: In an outboard motor having a fuel-injected two-cycle engine, engine speed, throttle setting, engine temperature and/or other variables are detected and a basic fuel injection volume determined. Fuel is supplied to each of the engine's cylinders according to the detected values. When the engine is operating at a high speed, trim angle and vessel speed are detected. The trim angle and vessel speed are used to correct the basic fuel injection volume determined before high speed operation of the engine is detected.

Abstract: In an air-fuel ratio control system for an internal combustion engine, a fuel injection amount to be injected from a fuel injector is set based on a monitored operating condition of the engine. The fuel injector injects a corresponding amount of fuel to the engine. An air-fuel ratio sensor monitors exhaust gas discharged from the engine and detects an air-fuel ratio. The system derives an injector sensitivity based on a current fuel injection amount and an output of the air-fuel ratio sensor and further derives, as an injector sensitivity deviation, a ratio between the derived injector sensitivity and an injector sensitivity estimated upon designing the system. The system further derives a sensitivity correction term based on the derived injector sensitivity deviation so as to correct the injector sensitivity. The system may also correct an air-fuel ratio sensor sensitivity in a similar manner.

Abstract: An electrical system for an engine of the type utilized to power an outboard motor is disclosed. The engine has a body with a crankshaft rotating therein. At least one fuel injector supplies fuel to the engine for combustion. The electrical system includes an electronic engine control unit for controlling at least the fuel injector based upon one or more sensed conditions. The electrical system also includes at least one sensor for providing data regarding one or more conditions. Preferably, at least an air pressure and intake air temperature sensor are provided. The sensors are mounted to a portion of the engine body adjacent the crankshaft, preferably via a vibration isolated bracket, for improving sensor accuracy and reliability.

Abstract: An air-cooled multi-cylinder engine including two temperature sensors each attached to different cylinders. The temperature difference between the two cylinders is detected by the temperature sensors. The air-fuel ratio in each cylinder is made the stoichiometric air-fuel ratio by decreasing the amount of fuel fed into higher temperature cylinders and increasing the amount of fuel fed into lower temperature cylinders.

Abstract: In a direct injection type gasoline engine for directly injecting fuel into each cylinder, fuel pressures supplied to each fuel injection valve are detected, and the fuel injection pulse width is detected according to the detected fuel pressures. Here, the fuel injection pulse width is corrected based on a value obtained by smoothing the detected values of the fuel pressures and at the same time, a smoothing level is changed according to the transitional or steady state of the engine, thereby achieving the response characteristic of correction at the transitional state and the stable correction at the steady state.

Abstract: A vapor collection canister vent valve contains both an electric pressure sensor for measuring evaporative emission space pressure during a diagnostic test and an electric actuator for operating the vent valve closed during a diagnostic test. Use of the valve in an evaporative emission control system reduces the number of connections, both electrical and fluid, that are required to install the valve in a system. The remote location of the pressure sensor damps the effect of pressure transients, such as those due to tank fuel slosh, on the sensor.

Abstract: The invention relates to a fuel injection system having an electrically actuatable injection pump which comprises a pre-stroke actuator for setting the start of injection and a flow rate actuator for setting the injection quantity. A control unit for controlling the injection quantity and start of injection emits an actuation signal which starts injection to the flow rate actuator, and an actuation signal for the start of injection to the pre-stroke actuator via an output lead for the actuation signal for the start of injection. According to the invention, the control unit protects the pre-stroke actuator against a short-circuit on the output lead by monitoring the control deviation at the start of injection between the actual value for the start of injection (detected by means of a needle movement sensor) and a desired value for the start of injection, which fixed as a function of the engine operating point.

Abstract: A high-pressure fuel injection system which has a fuel injection unit including an injector, a fuel pump for supplying a high-pressure fuel to the fuel injection unit, a motor for driving the fuel pump, a PID controller for controlling the operation of the motor, a device for measuring an actual fuel pressure in the fuel injection unit, a device for calculating a deviation of the actual fuel pressure from a predetermined desired fuel pressure and for inputting the deviation to the PID controller as an actuating signal, and a device for calculating a desired fuel injection quantity per injection from input signals indicating an engine speed, an accelerator opening, etc. A manipulated variable which is given as an output from the PID controller is supplied to the motor as an input to control the motor.

Abstract: A fuel measurement and control system for a gaseous fuel engine having a solenoid actuated fuel flow control valve which is electronically actuated to control a desired metering duration when the control system is operating in a fuel flow control mode. The fuel measurement and control system further includes mode control valve for switching the control system between a fuel flow control mode and a positive fuel shutoff mode, wherein the fuel flow control valve is prevented from opening when the control system is operating in a positive fuel shutoff mode. The fuel flow control valve includes a pressure balance chamber to balance the biasing forces acting on the valve from the gaseous fuel, wherein gaseous fuel is introduced into the pressure balancing chamber to provide the balancing forces.

Abstract: An apparatus and methods are provided for sensing movement of a fuel injector valve of a fuel injection system. The apparatus preferably includes a fuel pump for pumping fuel to flow to a combustion chamber of an engine and a first valve positioned in fluid communication with the fuel pump for allowing fuel to flow directly into the combustion chamber when in an open position. A second valve is positioned in fluid communication with the first valve and the fuel pump for allowing fuel to flow to the first valve when in an open position. A second valve actuator is positioned responsive to desired fuel injection for actuating the second valve. A sensor is positioned to sense movement of the first and second valves and the actuation of the second valve actuator. A movement differentiator is preferably positioned responsive to the sensor for differentiating a time of moving of the first valve from the time of moving of the second valve and the actuation of the second valve actuator.

Abstract: A control unit 15 of an air/fuel ratio control apparatus according to the present invention takes in signals output from various sensors detecting operational states of an engine, and controls the fuel injection amount and the ignition timing by executing the predetermined processing by using the taken-in signals, and outputting control signals obtained by the processing to each injector and an ignition coil connected to each ignition plug. Further, the amount to be injected in each cylinder is corrected, based on the integration value of fuel pressure changes detected by the fuel pressure sensor, on the basis of the found fact that the integration value of the fuel pressure changes for each cylinder well corresponds to the amount actually injected into the cylinder.

Abstract: A fuel system for an internal combustion engine (10) includes a controller (14) which controls the operation of an engine fuel pump (13). Signals are supplied to the controller by a transducer (16) which is responsive to the passage of teeth formed on the periphery of a wheel (12) which is mounted on the engine crankshaft. In order to generate an engine speed signal it is necessary to know the tooth spacing errors and these are determined by recording two time pulse sequences of signals from the transducer at different engine speeds and loads and then processing those signals to firstly determine the periodic component of the signals due to the fluctuation of engine speed which occurs due to the individual power strokes of the engine.

Abstract: According to the present invention, combustion properties of a gaseous fuel such as natural gas, utilized to fuel an internal combustion engine, are determined by measuring the velocity of sound in the gaseous fuel. This sound velocity measurement is utilized to control and adjust engine performance factors such as ignition timing, fuel flow rate, air/fuel ratio, fuel injection timing, and pilot fuel oil quantity and timing in dual fuel systems. The speed of sound in the gaseous fuel is used to define the hydrogen-to-carbon ratio in the fuel, which is employed in the invention to control and adjust various engine performance factors, and a number of display readouts.

Abstract: A fuel management system for a gaseous fuel internal combustion engine is disclosed in which a mass air flow sensor as well as a mass gas flow sensor provide input signals to an electronic control unit (ECU) which then determines the air/fuel ratio. The ECU in turn generates output signals to a fuel valve to control the mass of fuel flow to the engine and thus the air/fuel ratio. A turbocharger bypass valve, a precooler for the gaseous fuel supply, a pressure accumulator upstream from the fuel valve, as well as a system to calibrate the engine to the specific gaseous fuel is described to enhance the accuracy of the fuel management system. An improved pressure balanced valve for controlling the fuel flow to the engine is also provided as well as a cylinder pressure transducer to optionally provide an output signal to the ECU to determine the air/fuel ratio.