Abstract: Methods and systems are provided for diagnosing functionality of a check valve in a vehicle evaporative emissions system, where the check valve functions to prevent unmetered air from entering engine intake under conditions of engine intake manifold vacuum. In one example, a method may include diagnosing whether the check valve is stuck open based on a temperature change at the fuel vapor canister as monitored by a canister temperature sensor, and responsive to an indication that the check valve is stuck open, taking mitigating actions to reduce undesired emissions. In this way, functionality of such a check valve may be determined periodically, without additional sensors, thus reducing costs while improving emissions.

Abstract: A flow meter is disclosed having a meter body that is enveloped by a shroud having a compliant band disposed at least partially about the meter body. The shroud protects transducers and transducer cables. The shroud forms a chamber between the shroud and meter body, and includes a releasable portion to allow access into the chamber.

Abstract: There is provided an engine stroke determination apparatus. The engine stroke determination apparatus is for determining stroke of a single-cylinder four-stroke engine and includes a transistor igniter. The apparatus is configured to determine a compression stroke and an exhaust stroke by comparing voltages of ignition signals that are output in the compression stroke and the exhaust stroke by the transistor igniter.

Abstract: The invention provides an inter-cylinder air-fuel ratio imbalance abnormality detection device for a multi-cylinder internal combustion engine, in which when abnormality detection processing of detecting an inter-cylinder air-fuel ratio imbalance abnormality on the basis of revolution speed fluctuations of the multi-cylinder internal combustion engine and ignition timing control for controlling the ignition timing so as to restrict revolution speed fluctuations in the multi-cylinder internal combustion engine are implemented, the implementation of the ignition timing control is restricted when the abnormality detection processing is implemented, and an abnormality detection method to be used in such a device.

Abstract: An accumulating portion suspends the accumulation of an airflow meter output and a timer suspends the time count when a clutch semi-engagement detection signal is being output from a clutch semi-engagement detection portion. Thus, the airflow meter output obtained while the clutch semi-engagement detection signal was being output is excluded from the calculation of a total intake air amount. A comparing portion compares the calculated total intake air amount with a reference value obtained from a reference value setting portion. If the total intake air amount is smaller than the reference value, the Cold Start Strategy (CSS) control is determined as being abnormal and a CSS-abnormality signal is output.

Abstract: The invention provides an inter-cylinder air-fuel ratio imbalance abnormality detection device for a multi-cylinder internal combustion engine, in which when abnormality detection processing of detecting an inter-cylinder air-fuel ratio imbalance abnormality on the basis of revolution speed fluctuations of the multi-cylinder internal combustion engine and ignition timing control for controlling the ignition timing so as to restrict revolution speed fluctuations in the multi-cylinder internal combustion engine are implemented, the implementation of the ignition timing control is restricted when the abnormality detection processing is implemented, and an abnormality detection method to be used in such a device.

Abstract: A diagnostic system includes a temperature derivative module and a heater use module. The temperature derivative module determines a derivative of a temperature of one of a fluid of an engine of a vehicle and a component of the engine measured by a temperature sensor after a vehicle startup event. The heater use module selectively indicates that an engine heater was used before the vehicle startup event based on the derivative.

Abstract: An accelerator sensor that is mounted on an engine block may be used to detect vibration of a compression ignition engine, and the detected vibration signal is analyzed to determine the combustion timing of the engine. A method for detecting combustion timing may include measuring a block vibration signal generated in a combustion process of an engine, setting up a frequency area that is to be analyzed in the block vibration to divide the frequency area into wavelet scales, executing continuous wavelet transformations of the divided wavelet scales to extract respective result values thereof and to calculate differences between former result values and latter result values, comparing the calculated difference value with a predetermined value to store crank angles of pertinent timing if the calculated difference values exceed the predetermined value, and averaging the stored crank angles to determine combustion timing in a case that all wavelet scales are processed.

Abstract: A level adjusting circuit which adjusts input pulses from an antenna to a level suitable for determining the number of engine revolutions, is connected in a circuit that connects the antenna with a determining circuit. An optimum adjustment of the determination level by manual operation allows the pulses inputted to the determining circuit to be precisely determined at all times.

Abstract: An internal combustion engine torque estimation device that accurately estimates the torque of an internal combustion engine without being affected by engine speed changes. A reference signal, which is output at predetermined rotation angle intervals of a crankshaft for the engine, is acquired. In accordance with the reference signal, the amount of change in the rotation speed of the crankshaft is acquired as a rotational fluctuation. A filtering process is performed on the rotational fluctuation in synchronism with reference signal output timing to extract a frequency component synchronized with a combustion cycle of the engine. The torque of the engine is estimated in accordance with the extracted frequency component.

Abstract: A cetane number estimating device (1) comprises cylinders which are provided to an internal combustion engine where a part of the exhaust gas can be fed back from the exhaust system to the intake system, injection means (30) for injecting fuel into the cylinders, measuring means (40) for measuring the ignition timings in the cylinders, and estimating means (20) for estimating the cetane number of the fuel according to the measured ignition timing as well as any one of a first correlation between the ignition timing corresponding to the stage at which when one cylinder is in the intake stroke, another cylinder in the exhaust stroke exhausts non-burned gas and the cetane number and a second correlation between the ignition timing corresponding to the stage at which when one cylinder is in the intake stroke, another cylinder exhausts burned gas and the cetane number.

Abstract: An accelerator sensor that is mounted on an engine block may be used to detect vibration of a compression ignition engine, and the detected vibration signal is analyzed to determine the combustion timing of the engine. A method for detecting combustion timing may include measuring a block vibration signal generated in a combustion process of an engine, setting up a frequency area that is to be analyzed in the block vibration to divide the frequency area into wavelet scales, executing continuous wavelet transformations of the divided wavelet scales to extract respective result values thereof and to calculate differences between former result values and latter result values, comparing the calculated difference value with a predetermined value to store crank angles of pertinent timing if the calculated difference values exceed the predetermined value, and averaging the stored crank angles to determine combustion timing in a case that all wavelet scales are processed.

Abstract: An ignition timing measuring and display device of an internal combustion engine (1) having a magneto (A) includes a reference RPM signal pulse detector (2) for detecting a reference RPM signal pulse of the internal combustion engine (1) and an ignition noise pulse detector (4) for detecting ignition noise of an electromagnetic wave generated in the vicinity of an ignition plug (3) when ignition is carried out in the internal combustion engine (1) and calculates ignition timing generated by the magneto (A) based on the signal pulse and the ignition noise pulse and displays it. Since the ignition timing of the internal combustion engine can be easily monitored, maintenance can be carried out to the internal combustion engine and an ignition device to realize a necessary operating performance of the internal combustion engine.

Abstract: An ignition timing measuring and display device of an internal combustion engine (1) having a magneto (A) includes a reference RPM signal pulse detector (2) for detecting a reference RPM signal pulse of the internal combustion engine (1) and an ignition noise pulse detector (4) for detecting ignition noise of an electromagnetic wave generated in the vicinity of an ignition plug (3) when ignition is carried out in the internal combustion engine (1) and calculates ignition timing generated by the magneto (A) based on the signal pulse and the ignition noise pulse and displays it. Since the ignition timing of the internal combustion engine can be easily monitored, maintenance can be carried out to the internal combustion engine and an ignition device to realize a necessary operating performance of the internal combustion engine.

Abstract: An internal combustion engine torque estimation device that accurately estimates the torque of an internal combustion engine without being affected by engine speed changes. A reference signal, which is output at predetermined rotation angle intervals of a crankshaft for the engine, is acquired. In accordance with the reference signal, the amount of change in the rotation speed of the crankshaft is acquired as a rotational fluctuation. A filtering process is performed on the rotational fluctuation in synchronism with reference signal output timing to extract a frequency component synchronized with a combustion cycle of the engine. The torque of the engine is estimated in accordance with the extracted frequency component.