Abstract: Apparatus (10) for a hydraulic valvetrain system (90) comprising: a first oil retaining means 5 (12), a second oil retaining means (20) and an oil conveyance means (14, 16) having a first end (18) operably connected to the first oil retaining means (12) and a second end (22) operably connected to the second oil retaining means (20). The second oil retaining means (20) is configured to receive oil from the first oil retaining means (12) via the oil conveyance means (14, 16), the first oil retaining means (12) is configured to receive oil from the oil 10 conveyance means (14, 16) and the oil conveyance means (14, 16) is configured to receive oil from the second oil retaining means (20).

Abstract: Apparatus (10) for a hydraulic valvetrain system (90) comprising: a first oil retaining means 5 (12), a second oil retaining means (20) and an oil conveyance means (14, 16) having a first end (18) operably connected to the first oil retaining means (12) and a second end (22) operably connected to the second oil retaining means (20). The second oil retaining means (20) is configured to receive oil from the first oil retaining means (12) via the oil conveyance means (14, 16), the first oil retaining means (12) is configured to receive oil from the oil 10 conveyance means (14, 16) and the oil conveyance means (14, 16) is configured to receive oil from the second oil retaining means (20).

Abstract: In a method of monitoring for a misfire event in an internal combustion engine signals representative of engine speed are monitored for successive engine revolutions subsequent to each firing event. The monitored signals are stored (e.g., in a buffer) and processed to detect changes in the monitored speed signals. Changes in monitored speed signals that are indicative of an actual misfire event are detected and a misfire count is changed in response thereto.

Abstract: An internal combustion engine includes an exhaust system, an oxygen sensor in the exhaust system and a sensor malfunction monitor. The sensor malfunction monitor measures a rate of change of a signal from the sensor on detecting a turning point of the signal and detects a malfunction when a rate of change of the signal exceeds a threshold. Alternatively, the sensor malfunction monitor measures a response time interval starting from a point in time at which a diagnostic function begins to force an air-fuel ratio to change (e.g., from lean-to-rich or rich-to-lean) and ends at a point in time when a turning point of the signal is detected. The sensor malfunction monitor detects a malfunction when the delay time of the response time interval, or average delay time from a plurality of measured response time intervals, exceeds a time threshold.

Abstract: In a method of monitoring for a misfire event in an internal combustion engine signals representative of engine speed are monitored for successive engine revolutions subsequent to each firing event. The monitored signals are stored (e.g., in a buffer) and processed to detect changes in the monitored speed signals. Changes in monitored speed signals that are indicative of an actual misfire event are detected and a misfire count is changed in response thereto.

Abstract: An internal combustion engine includes an exhaust system, an oxygen sensor in the exhaust system and a sensor malfunction monitor. The sensor malfunction monitor measures a rate of change of a signal from the sensor on detecting a turning point of the signal and detects a malfunction when a rate of change of the signal exceeds a threshold. Alternatively, the sensor malfunction monitor measures a response time interval starting from a point in time at which a diagnostic function begins to force an air-fuel ratio to change (e.g., from lean-to-rich or rich-to-lean) and ends at a point in time when a turning point of the signal is detected. The sensor malfunction monitor detects a malfunction when the delay time of the response time interval, or average delay time from a plurality of measured response time intervals, exceeds a time threshold.

Abstract: An internal combustion engine includes an exhaust system, an oxygen sensor in the exhaust system and a sensor malfunction monitor. The sensor malfunction monitor measures a rate of change of a signal from the sensor on detecting a turning point of the signal and detects a malfunction when a rate of change of the signal exceeds a threshold.

Abstract: An engine speed variation after one power stroke from a misfire has an opposite sign (plus or minus) relative to an engine speed variation at a misfire. A computer determines whether the misfire exists in the subject cylinder based on the engine speed variation between the subject cylinder and the subject cylinder after one power stroke. In order to detect any kinds of misfire, the computer computes a difference value between a current engine speed variation and an engine speed variation before 360° CA or after 360° CA, a difference value between a current engine speed variation and an engine speed variation before 720° CA or after 720° CA, and a difference value between a current engine speed variation and an engine speed variation before 720/(cylinder number)° CA or after 720/(cylinder number)° CA. These three difference values are respectively compared with a misfire determination value to perform a misfire detection.

Abstract: A diagnosis device calculates a lean-direction responsiveness characteristic and a rich-direction responsiveness characteristic of the exhaust gas sensor. The lean-direction responsiveness represents a responsiveness of the sensor in a case that an air-fuel ratio is controlled in such a manner as to be varied in a lean direction. The rich-direction responsiveness represents a responsiveness of the sensor in a case that the air-fuel ratio is controlled in such a manner as to be varied in a rich direction. The diagnosis device determines whether the exhaust gas sensor deteriorates based on at least one of the lean-direction responsiveness characteristic and the rich-direction responsiveness characteristic, and on a comparison result between the lean-direction responsiveness characteristic and the rich-direction responsiveness characteristic.

Abstract: A diagnosis device calculates a lean-direction responsiveness characteristic and a rich-direction responsiveness characteristic of the exhaust gas sensor. The lean-direction responsiveness represents a responsiveness of the sensor in a case that an air-fuel ratio is controlled in such a manner as to be varied in a lean direction. The rich-direction responsiveness represents a responsiveness of the sensor in a case that the air-fuel ratio is controlled in such a manner as to be varied in a rich direction. The diagnosis device determines whether the exhaust gas sensor deteriorates based on at least one of the lean-direction responsiveness characteristic and the rich-direction responsiveness characteristic, and on a comparison result between the lean-direction responsiveness characteristic and the rich-direction responsiveness characteristic.