Abstract: An apparatus for determining properties of fluid flowing into a well includes an inflow channel providing a path for fluid to a pipe, a heater arranged to heat at least part of the fluid in the inflow channel, and a temperature sensor arranged to measure the temperature of the fluid in the inflow channel.

Abstract: In an engine system including an engine, and an exhaust gas recirculation device including a communicating pipe that communicates an exhaust pipe of the engine with an intake pipe, and a valve provided in the communicating pipe, and an electronic control unit, and its control method, the electronic control unit estimates the pressure in the intake pipe as an estimated intake pressure, and performs a jamming diagnosis to determine whether foreign matter is stuck in the valve, by comparing an intake pressure difference between a detected intake pressure and the estimated intake pressure with a threshold value, when a diagnosis condition including an opening change condition that the target opening becomes equal to or larger than a first predetermined opening and then becomes equal to or smaller than a second predetermined opening that is smaller than the first predetermined opening is satisfied.

Abstract: A physical quantity measurement device includes a housing forming a measurement flow path through which the fluid flows and a container space that houses a part of a detection unit. An inner surface of the housing includes a housing intersecting surface that intersects an arrangement direction in which the measurement flow path and the container space are arranged, a housing flow path surface extending from the housing intersecting surface toward the measurement flow path, and a housing container surface extending from the housing intersecting surface toward the container space. The housing includes a housing partition that protrudes from the inner surface toward the detection unit and contacts the detection unit between the housing and the detection unit such that the housing partition separates the measurement flow path and the container space from each other.

Abstract: A physical quantity measurement device includes a housing forming a measurement flow path including a measurement inlet and a measurement outlet. The measurement flow path includes a sensor path in which a physical quantity sensor is disposed, an upstream curved path curved to extend from the sensor path toward the measurement inlet, and a downstream curved path curved to extend from the sensor path toward the measurement outlet. An inner surface of the housing includes an upstream outer curved surface that defines an outer outline of a curved part of the upstream curved path, and a downstream outer curved surface that defines an outer outline of a curve part of the downstream curved path. A degree of recess of the downstream outer curved surface is larger than a degree of recess of the upstream outer curved surface.

Abstract: A method for checking the function of a pressure sensor in the air intake tract or gas outlet tract of an internal combustion engine and to an engine control unit for carrying out the method and based on measuring dynamic pressure oscillations of the intake air or the exhaust gas by the relevant pressure sensor and, on the basis of the pressure oscillation signal obtained, respectively determining with the aid of a discrete Fourier transformation for a number of selected signal frequencies in each case a value of a specific operating characteristic of the internal combustion engine and deviation values of the values determined for the different signal frequencies from one another. Depending on whether deviation values determined fall below or exceed a predetermined limit value, the satisfactory function of the pressure sensor is confirmed, or a malfunction of the pressure sensor is diagnosed.

Abstract: To obtain a physical quantity detection device that can prevent a thermal influence on a sensor due to downsizing. A physical quantity detection device 20 of the present invention includes a measuring unit 213 protruding from an inner wall of a main passage 22 toward a passage center of the main passage. The physical quantity detection device 20 includes at least one of a flow sensor 205 that detects a flow rate of a measured gas 2, an intake air temperature sensor 203 that detects temperature, a pressure sensor 204 that detects pressure, and a humidity sensor 206 that detects humidity, and the sensors are disposed along a protruding direction of the measuring unit 213.

Abstract: A fresh air and exhaust gas control method for an engine includes monitoring parameters of an engine in an operational state using a plurality of sensors and generating engine state estimates using an engine observer model. The engine observer model represents an intake manifold volume, an exhaust manifold volume, and a charge air cooler volume. The method also includes generating a turbocharger rotational speed estimate using a turbocharger model and calculating a fresh air flow correction factor. The method further includes determining a desired air throttle position and a desired EGR valve position based on setpoint commands, the monitored engine parameters, the fresh air flow correction factor, the engine state estimates, and the turbocharger rotational speed estimate. The method additionally includes adjusting the air throttle based on the desired air throttle position and adjusting the EGR valve based on the desired EGR valve position.

Abstract: A valve assembly comprises: a valve housing comprising an interior cavity having upstream side and a downstream side; and a valve member movable within the valve housing between a closed position in which flow between the upstream side and the downstream side is prevented or substantially prevented and one or more open positions in which flow between the upstream side and the downstream side is enabled. The valve assembly further comprises: a sensor mounting flange on an exterior surface of the valve housing; a first bore in the valve housing linking the upstream side of the valve housing and the sensor mounting flange; and a second bore in the valve housing linking the downstream side of the valve housing and the sensor mounting flange; such that a sensor configured to measure a differential between the upstream side and the downstream side is mountable directly on the valve assembly.

Abstract: In order to provide a temperature and humidity sensor with improved reliability, the temperature and humidity sensor in which all or part of a case of the temperature and humidity sensor is inserted into a main duct for causing gas to pass through and which detects humidity of the gas, includes: a first sub-passage configured as a part of the case, a part of the gas passing through the main duct flowing in substantially the same direction as a flow in the main duct; a throttle section provided between an inlet and an outlet of the first sub-passage and on an inner surface of the first sub-passage, the throttle section having a throttle whose cross-sectional area is smaller than an average cross-sectional area of the entire first sub-passage; and a second sub-passage which connects an upstream side and a downstream side of the throttle section and is different from the first sub-passage.

Abstract: A sensor device is disposed in an intake passage through which intake air flows to an internal combustion engine. The sensor device includes a humidity sensor that generates a signal according to a humidity of the intake air flowing through the intake passage. A choke portion is defined in the intake passage to decrease a cross-sectional area of the intake passage. The humidity sensor is arranged on the choke portion.

Abstract: An air flow rate measurement device disposed in an intake passage by passing through an insertion hole of an intake pipe of an engine to communicate inside and outside includes: a case having a bypass channel, a part of air flowing through the intake passage flows into the bypass channel; a flow rate sensor arranged inside of the case, and having a flow rate detector which detects a flow rate of air flowing through the bypass channel; and a humidity sensor arranged outside of the case, and having a humidity detector which detects a humidity of air flowing through the intake passage. A surface of the humidity detector is arranged to oppose a wall of the case through a clearance.

Abstract: The present disclosure provides a flow rate measuring device including a flow rate detecting body, a humidity detecting body, and a base. The flow rate detecting body protrudes inside of an intake passage. The humidity detecting body protrudes inside of the intake passage at a position away from the flow rate detecting body. The base is connected to the flow rate detecting body and the humidity detecting body. The humidity detecting body holds a sensor chip that includes a humidity detecting element sensitive to the humidity of the intake air. A length, along a flow direction of the intake air, of an exposed portion of the humidity detecting body is defined as a referential length. The humidity detecting element exists within a range from an upstream end of the exposed portion of the humidity detecting body to a position of half the referential length.

Abstract: A method for determining a signal offset between a crankshaft angle signal and a combustion chamber pressure signal includes: measuring the combustion chamber pressure signal; shifting an alignment of the measured combustion chamber pressure signal with respect to the crankshaft angle signal by a plurality of respective offset angles to generate a plurality of offset combustion chamber pressure signals; reconstructing the offset combustion chamber pressure signals using a plurality of predetermined inherent pressure curves to generate reconstructed combustion chamber pressure signals; determining reconstruction errors of the reconstructed combustion chamber pressure signals as a function of differences between the offset combustion chamber pressure signals and the reconstructed combustion chamber pressure signals; and determining the signal offset between the crankshaft angle signal and the combustion chamber pressure signal as a one of the plurality of offset angles producing the reconstruction error having

Abstract: An airflow meter includes a flow rate sensor for measuring a flow rate of intake air sucked into an engine, a humidity sensor that outputs an intake air humidity signal in accordance with humidity of the intake air, an intake air temperature sensor that outputs an intake air temperature signal in accordance with temperature of the intake air, and a humidity correction section that corrects the intake air humidity signal based on the intake air temperature signal.

Abstract: In one aspect, an engine controller for an engine including multiple working chambers is described. The engine controller includes a mass air charge determining unit that estimates a mass air charge or amount of air to be delivered to a working chamber. Firing decisions made for a firing window of one or more firing opportunities are used to help determine the mass air charge. The engine controller also includes a firing controller, which is arranged to direct firings to deliver a desired output. Fuel is delivered to a working chamber based on the estimated mass air charge.

Abstract: A flow sensor comprises a flow restriction disposed within a passage such that a fluid passing through the passage must pass through the flow restriction. The flow sensor also has an upstream pressure sensor coupled to the passage at a point upstream of the flow restriction and configured to measure and provide an upstream pressure of the fluid within the passage, a downstream pressure sensor coupled to the passage at a point downstream of the flow restriction and configured to measure and provide a downstream pressure of the fluid within the passage, and a temperature sensor coupled to the passage and configured to measure and provide a temperature of the fluid within the passage. The flow sensor also includes a flow sensor processor coupled to the upstream and downstream pressure sensors and the temperature sensor and configured to accept measurements therefrom and calculate a compensated flow rate based at least in part on the measured pressures and temperature.

Abstract: A method for increasing a reliability of a transducer is provided. The transducer has a first and a second IC, wherein the two ICs each have substantially the same monolithically integrated circuit components with one sensor apiece, and a signal contact for bidirectional data transmission. A reference contact on each of the two ICs is connected to or disconnected from the signal contact by a controllable switch, and a signal generated as a function of the physical quantity sensed by the relevant sensor is applied to the signal contact. The two ICs are integrated into a common IC package, and a supply voltage contact of the first IC is connected to a first package contact, and the first package contact is connected to a first terminal of a control unit, and the supply voltage contact of the second IC is connected to a second package contact.

Abstract: An internal combustion engine has a crankcase and a crankcase ventilation system having a switchable shut-off valve, and sensors that detect different operating parameters of the engine, including a load variable of the engine. An estimated load parameter is determined based on the different detected operating parameters using a dynamic model, and a corrective value of a characteristic value is determined as a function of a deviation between the estimated load variable and the detected load variable. To implement a diagnosis, diagnosis switching cycle(s) are controlled, in which the shut-off valve is set to a closed switched position for a first time and set to an open switched position for a second time. A diagnosis value representative of a shut-off valve being in a correct or incorrect state is determined based on a change to the corrective value in response to the one or the plurality of diagnosis switching cycles.

Abstract: An internal combustion engine, in particular a gas engine, for a motor vehicle, includes a charge air cooler arranged in an air mass flow feed upstream of an apparatus for mixing in fuel, and a measuring device for determining the air mass flow. The measuring device has a sensor system for measuring a pressure loss across the charge air cooler and a processing unit as evaluation unit for calculating the air mass flow at least from the pressure loss which is measured by the sensor system and a charge air cooler model stored in the processing unit. The charge air cooler forms a geometrically constant throttle for the air mass flow which is flowing through.

Abstract: Disclosed is a fault diagnosis apparatus for an airflow meter for determining that the airflow meter has a fault when a divergence ratio, i.e., a divergence value of an estimated intake-air quantity with respect to an actual intake-air quantity obtained by the airflow meter is greater than a fault-determination reference value determined based on a rotation speed of an internal combustion engine. As the engine speed reduces, an upper-limit diagnosis criterion increases and a lower-limit diagnosis criterion decreases, so as to narrow an area for determining that the airflow meter has a fault. Hence, the fault diagnosis for the airflow meter can be performed in the entire engine rotation speed range, i.e., in the entire operation range of the internal combustion engine, thus preventing a deterioration in the exhaust performance, which may occur owing to a failure in the airflow meter, beforehand.

Abstract: In a method for determining a pressure at the output of an exhaust gas system of an internal combustion engine system of a vehicle, a mass flow through the internal combustion engine system and an ambient pressure at a fresh air supply of the internal combustion engine system are detected. The pressure at the output of the exhaust gas system is determined as a function of the mass flow, the ambient pressure and throttling of the mass flow through the internal combustion engine system.

Abstract: A method for adjusting an oxygen sensor measurement within an exhaust gas feedstream output from an internal combustion engine based on humidity includes monitoring relative humidity of ambient air obtained from a humidity sensor. Specific humidity at the oxygen sensor is modeled based on the relative humidity. The oxygen sensor measurement is adjusted based on the modeled specific humidity at the oxygen sensor.

Abstract: An electronic control unit (ECU) is equipped with a turbine passing path constant that corresponds to a time required for exhaust gas to flow to an air-fuel ratio sensor via a turbine of a turbosupercharger, and a bypass path constant that corresponds to a time required for exhaust gas to flow to the air-fuel ratio sensor via a bypass passage. The ECU calculates first and second fuel injection correction amounts and in which the path constants and are reflected, respectively. The ECU selects one of the fuel injection correction amounts and based on at least an open or closed state of the waste gate valve (WGV), corrects a fuel injection amount using the selected fuel injection correction amount. It is thus possible to appropriately compensate for differences in exhaust path lengths and air-fuel ratio fluctuations that arise due to opening or closing of the WGV.

Abstract: An estimation device for a cylinder intake air amount in an internal combustion engine is obtained which can estimate an amount of air actually sucked into a cylinder with a high degree of accuracy by using a physical model of an intake system. A volumetric efficiency corresponding value is calculated based on an exhaust efficiency (a linear function of intake pipe internal pressure) which is an index indicating an amount of residual gas which is an exhaust gas after combustion remaining in the cylinder without being discharged from the interior of the cylinder to an exhaust pipe, and an intake efficiency (a linear function of intake pipe internal pressure) which is an index indicating an amount of air coming into the cylinder from an intake pipe excluding the residual gas, whereby the estimation is carried out to a high degree of accuracy with a small number of adaptation constants.

Abstract: A sensor for detecting the mass flow rate and the temperature of a fluid flow has a mass flow rate sensor having a mass flow rate sensor element, a temperature sensor having a temperature sensor element, and an interface for power supply. The sensor converts the measured values detected in analog by the mass flow rate sensor element and the temperature sensor element into digital output signals. In order to specify the simplest and most economical sensor possible for detecting the mass flow rate and the temperature of a fluid flow, at least one analog/digital converter is arranged in the sensor, which analog/digital converter converts the analog measured values of the mass flow rate sensor element and/or the analog measured value of the temperature sensor element into digital output signals and provides the digital output signals at a single digital interface.

Abstract: A method for checking the functioning of a ventilation apparatus for ventilating a crankcase connected via the ventilation apparatus to an air supply system of the internal combustion engine includes: determining a pressure difference between an ambient pressure and a crankcase pressure in the crankcase; identifying a fault in the ventilating apparatus as a function of the pressure difference if an enabling condition is met; the enabling condition being met if an air mass flow in the air supply system, filtered by a low-pass filter, exceeds a first threshold value in terms of absolute value.

Abstract: An apparatus and a system is provided that may be utilized to determine air flow through an air filter and/or a plurality of air filters. The present invention utilizes a demonstration apparatus to illustrate the differences in air flow and air restriction between a plurality of different air filters and filtration media. The apparatus and system utilizes a common plenum which subjects the plurality of air filters to the same differential pressure. The air flows through a first side of the air filter and is measured on the second side of the air filter by utilizing a wind meter or similar device to gauge the amount of air flow velocity of the second side of the filter. Additionally, the apparatus and system utilizes a display means to illustrate the differing air velocity through the second side of the air filter.

Abstract: An air flow measuring device includes a housing, flow sensor, and a humidity sensor. The housing defines a bypass flow passage through which intake it passes. A part of intake air is taken into the bypass flow passage to pass through the bypass flow passage. The flow sensor includes a sensing part disposed in the bypass flow passage, and produces a signal which is in accordance with the flow rate of intake air as a result of heat transfer between intake air taken into the bypass flow passage and the sensing part. The humidity sensor includes a sensing part exposed to the intake passage, and projects from an outer wall of the housing into the intake passage. The humidity sensor produces a signal which is in accordance with humidity of intake ail flowing through the intake passage.

Abstract: A system according to the present disclosure includes a pressure estimation module and a fault detection module. The pressure estimation module estimates a pressure of hydraulic fluid in a valve actuation system that actuates at least one of an intake valve and an exhaust valve of an engine. The fault detection module compares the estimated pressure to a pressure measured by a pressure sensor disposed in the valve actuation system and detects a fault in the pressure sensor based on a difference between the estimated pressure and the measured pressure.

Abstract: An arrangement of a mass intake air flow measurement device suitable for integrating a humidity sensing device as well as a temperature sensing device and a pressure sensing device is provided. A second bypass passage 501 bypassing a bypass passage 205 is formed and a humidity sensing device 500 is mounted in the second bypass passage 501. A second bypass passage inlet 502 and a second bypass passage outlet 503 formed in a wall surface of the bypass passage 205 are opened parallel to the direction of flow of air flowing in the bypass passage 205.

Abstract: In relation to a humidity sensor sensitive to water and contamination, a sensor implementation structure that achieves both protection performance against water and contaminants and measurement performance such as humidity responsiveness is provided. A sensor structure has a mass airflow measurement element that measures a mass airflow flowing in an intake pipe, a humidity sensing element that senses humidity of air flowing in the intake pipe, a housing structural component having a connector that carries out input/output to/from outside and a terminal component of the connector, and a bypass passage that is composed by using part of the housing structural component and takes in part of the air that flows in the intake pipe, the mass airflow measurement element being mounted in the bypass passage; wherein space is provided in the housing structural component in the vicinity of the bypass passage, the humidity sensing element is mounted in the space.

Abstract: A method for determining a cylinder air charge for an internal combustion engine includes determining engine operating parameters including an intake air charge density, an engine delta pressure as a ratio of an intake manifold pressure to an exhaust pressure, and an engine speed. An open-throttle volumetric efficiency corresponding to the engine operating parameters is determined, and a closed-throttle volumetric efficiency corresponding to the engine operating parameters is also determined. The cylinder air charge is determined using a selected one of the open-throttle volumetric efficiency and the closed-throttle volumetric efficiency.

Abstract: A method for checking the functioning of a ventilation apparatus for ventilating a crankcase connected via the ventilation apparatus to an air supply system of the internal combustion engine includes: determining a pressure difference between an ambient pressure and a crankcase pressure in the crankcase; identifying a fault in the ventilating apparatus as a function of the pressure difference if an enabling condition is met; the enabling condition being met if an air mass flow in the air supply system, filtered by a low-pass filter, exceeds a first threshold value in terms of absolute value.

Abstract: A method of operating an engine having an after-treatment system that treats exhaust gas from the engine with an oxidation catalyst includes adjusting the operation of the engine to increase the temperature of the exhaust gas, continuously sensing a cylinder pressure with a pressure sensor disposed at at least one cylinder of the engine to identify a unstable combustion event, i.e., an engine misfire, and adjusting the operation of the engine to prevent a future unstable combustion event when the unstable combustion event is detected.

Abstract: A method of valve lift failure detection may include determining first and second intake air pressures in an engine having intake valve lifters that selectively operate intake valves in first and second lift modes. The first intake air pressure may correspond to an intake stroke of a first piston of the engine when the engine is commanded to operate in the first lift mode and the second intake air pressure may correspond to an intake stroke of a second piston of the engine when the engine is commanded to operate in the first lift mode. The method may further include determining a difference between the first and second intake air pressures and diagnosing an intake valve lifter failure when the difference exceeds a predetermined limit.

Abstract: A system and method are provided for estimating the flow rate of air entering an air inlet of a turbocharger compressor. A first pressure value corresponds to pressure at or near the air inlet of the compressor, and a second pressure value corresponds to pressure at or near the air outlet of the compressor. A temperature value corresponds to a temperature at or near the air inlet of the compressor, and a speed value corresponds to an operating speed of the turbocharger. The flow rate of air entering the air inlet of the turbocharger compressor is illustratively estimated as a function of the first pressure value, the second pressure value, the temperature value and the speed value.

Abstract: An air flow measuring device includes a housing, flow sensor, and a humidity sensor. The housing defines a bypass flow passage through which intake it passes. A part of intake air is taken into the bypass flow passage to pass through the bypass flow passage. The flow sensor includes a sensing part disposed in the bypass flow passage, and produces a signal which is in accordance with the flow rate of intake air as a result of heat transfer between intake air taken into the bypass flow passage and the sensing part. The humidity sensor includes a sensing part exposed to the intake passage, and projects from an outer wall of the housing into the intake passage. The humidity sensor produces a signal which is in accordance with humidity of intake ail flowing through the intake passage.

Abstract: A waterproof connecting structure for a pipe for connecting an intake passage of an internal combustion engine and an external gas detector to convey gas into the intake passage. The structure includes a connecting space to which the pipe is connected and a partition wall formed between the intake passage and the connecting space. The connecting space has a larger diameter than the pipe. The partition wall includes an elongate hole for placing the interior of the intake passage and the connecting space in fluid communication. This configuration prevents intrusion of droplets drifting in through intake air and allows a high degree of freedom for location of the pipe.

Abstract: A method for determining at least one air system variable in an air supply system of an internal combustion engine in successive, discrete calculation steps, a differential equation being provided with respect to the air system variable based on measured and/or modeled variables, which describe conditions in the air supply system, a difference equation being formed for the quantization of the differential equation according to an implicit method, and the difference equation being solved in each discrete calculation step, in order to obtain the air system variable.

Abstract: A method for providing a characteristic quantity for a state of an air system of a supercharged internal combustion engine includes: detecting a characteristic quantity measured value as characteristic quantity information with the aid of a sensor; providing a characteristic quantity model, using which a characteristic quantity model value is computed on the basis of one or more quantities different from the characteristic quantity measured value; and providing the characteristic quantity either based on the characteristic quantity measured value or on the characteristic quantity model value computed by the characteristic quantity model, as a function of a state of the air system.

Abstract: A supercharged internal combustion engine in a motor vehicle includes a venting device for the crankcase of the internal combustion engine and a compressor for supercharging the internal combustion engine. A discharge opening for discharging the crankcase gas is provided upstream of the compressor and a sensor for determining the charge pressure of the compressor is provided downstream of the compressor. The discharge opening is connected to the crankcase by a first connection for the airflow, in particular a hose connection. In order to cost-effectively monitor the venting of the crankcase of the internal combustion engine, an opening, to which the charge pressure of the compressor is applied, is provided downstream of the compressor. The first connection for the airflow includes a closing device for closing the opening to which the charge pressure is applied, wherein the closing device closes the opening if the first connection is connected to the discharge opening.

Abstract: A method for estimating an oxygen concentration in an intake manifold of a diesel engine utilizing exhaust gas recirculation includes monitoring engine operation, monitoring an exhaust gas recirculation valve, and monitoring an exhaust air fuel ratio. When the engine operates in steady state with the exhaust gas recirculation valve in the closed position, a volumetric efficiency for the engine is updated. A partial pressure due to exhaust gas recirculation within the intake manifold based upon the updated volumetric efficiency is determined, and an estimated oxygen concentration within the intake manifold based upon the partial pressure due to exhaust gas recirculation within the intake manifold and the exhaust air fuel ratio is determined. Operation of the engine is controlled based upon the estimated oxygen concentration within the intake manifold.

Abstract: In relation to a humidity sensor sensitive to water and contamination, a sensor implementation structure that achieves both protection performance against water and contaminants and measurement performance such as humidity responsiveness is provided. A sensor structure has a mass airflow measurement element that measures a mass airflow flowing in an intake pipe, a humidity sensing element that senses humidity of air flowing in the intake pipe, a housing structural component having a connector that carries out input/output to/from outside and a terminal component of the connector, and a bypass passage that is composed by using part of the housing structural component and takes in part of the air that flows in the intake pipe, the mass airflow measurement element being mounted in the bypass passage; wherein space is provided in the housing structural component in the vicinity of the bypass passage, the humidity sensing element is mounted in the space.

Abstract: A method and system for controlling an internal combustion power train, whereby the values of various operating parameters of the power train are measured by means of a number of sensors, and operation of the engine is monitored by means of at least one control unit, which is physically separate from the engine block and connected to the sensors; at least one pressure sensor is housed in the control unit, is physically separate from the engine block, and determines the intensity of pressure waves generated by the power train; and the control unit determines the value of at least one operating parameter of the power train as a function of the intensity of the pressure waves generated by the power train.

Abstract: An arrangement of a mass intake air flow measurement device suitable for integrating a humidity sensing device as well as a temperature sensing device and a pressure sensing device is provided. A second bypass passage 501 bypassing a bypass passage 205 is formed and a humidity sensing device 500 is mounted in the second bypass passage 501. A second bypass passage inlet 502 and a second bypass passage outlet 503 formed in a wall surface of the bypass passage 205 are opened parallel to the direction of flow of air flowing in the bypass passage 205.

Abstract: An arrangement of a mass intake air flow measurement device suitable for integrating a humidity sensing device as well as a temperature sensing device and a pressure sensing device is provided. A second bypass passage bypassing a bypass passage is formed and a humidity sensing device is mounted in the second bypass passage. A second bypass passage inlet and a second bypass passage outlet formed in a wall surface of the bypass passage are opened parallel to the direction of flow of air flowing in the bypass passage.

Abstract: A fuel injection control apparatus includes: an internal combustion engine; a fuel injection unit provided in the internal combustion engine; an intake state detection unit that detects an intake state value indicating an intake state of the internal combustion engine, and that outputs an intake state signal; and a control unit to which the intake state signal is input, that determines based on the intake state signal whether or not the internal combustion engine is on an intake stroke, and that controls the fuel injection unit so that an initial fuel injection is performed in order to start up the engine when the control unit determines that the engine is on an intake stroke.

Abstract: In a non-critical pressure region where a pressure ratio [Pm/Pthrup(i?1)] of an intake air pressure Pm (throttle downstream pressure) detected by an intake air pressure sensor to a previous throttle upstream pressure Pthrup(i?1) is greater than a predetermined value B, the previous throttle upstream pressure Pthrup(i?1) is substituted for one of two terms of the throttle upstream pressures Pthrup(i) included in an intake system model so that present throttle upstream pressure Pthrup(i) is calculated. In a critical pressure region where the pressure ratio is less than or equal to the predetermined value B, a physical value f(Pm/Pthrup(i)) using a pressure ratio [Pm/Pthrup(i)] of the intake air pressure Pm to a present throttle upstream pressure Pthrup(i) as a parameter is regarded as a steady value fc so that the present throttle upstream pressure Pthrup(i) is calculated.

Abstract: A method of identifying misfires in an engine including: running the engine; measuring the pressure pulses from the exhaust; generating a waveform from the measured pulses; dividing the waveform into segments; associating each waveform segment with the cylinder which generated the pulse; and examining each segment for features which indicate a misfire. Also disclosed is methodology for checking the performance of an engine including cam timing and identifying the probable cause(s) of misfires. This includes generating a cylinder pressure waveform from the measured pressure changes in a cylinder and analyzing the magnitude and timing of at least one of the pressure changes in such cylinder. Further disclosed is methodology for analyzing the pressure changes in the engine's intake manifold and in the crankcase. Finally, additional diagnostic procedures are disclosed for: checking the ignition timing of an engine; and using the apparatus and methods with additional instrumentation including gas analyzers.

Abstract: A pressure differential valve apparatus that includes a valve, the valve having a valve head and a valve stem connected perpendicular to the valve head, the valve head having a valve face with an opening that continues inside an interior of the valve head to an intersection with the valve stem and along a length of the valve stem to a top of the valve stem, wherein the apparatus allows unobstructed pressure readings when the valve face is rotated in a radial direction within an area of flow of a cylinder head.