Abstract: A method and an arrangement for operating a drive motor of a vehicle are suggested. A resulting desired torque for controlling the drive motor is pregiven in dependence upon the driver command torque and additional desired torque quantities. To limit the resulting desired torque, a motor minimum torque is provided which is derived from the lost torques and is dependent upon rpm.

Abstract: A method and an arrangement for operating a drive unit of a vehicle are suggested. Starting from a driver command torque which is converted into a resulting desired torque while considering additional torques, a correction of the resulting desired torque is undertaken in dependence upon the loss torques, which are not available for the drive. For realizing a negative torque command of the driver, the driver command torque is corrected with the loss torque weighted in dependence upon accelerator pedal position and rpm.

Abstract: A engine control device includes a failure judgment means for making at least a failure judgment of an intake pipe pressure sensor. The failure judgment means includes a first data processing for outputting an estimated intake pipe pressure signal, a second data processing for outputting a modification estimated intake pipe pressure signal in which the estimated intake pipe pressure signal is modified, and a failure judgment processing for making a failure judgment of at least the intake pipe pressure sensor by comparing the measured intake pipe pressure signal with the modification estimated intake pipe pressure signal. The modification estimated intake pipe pressure signal has a change portion changing between a change portion of the estimated intake pipe pressure signal and a change portion of the measured intake pipe pressure signal, when the throttle valve opening degree is changed.

Abstract: A control system for an internal combustion engine having a plurality of cylinders and a switching mechanism for switching between an all-cylinder operation in which all of the cylinders is operated and a partial-cylinder operation in which at least one of the plurality of cylinders is halted. Operating parameters of a vehicle driven by the engine is detected. The all-cylinder operation or the partial-cylinder operation is performed according to the detected operating parameters. An oxygen concentration sensor is provided in an exhaust system corresponding to the at least one cylinder which is halted during the partial-cylinder operation. A failure of the oxygen concentration sensor is diagnosed in a predetermined operating condition including a fuel-cut operation of the engine upon deceleration. The partial-cylinder operation is permitted after completion of the failure diagnosis.

Abstract: An intake quantity control apparatus for an internal combustion engine which controls a valve opening characteristic and intake pressure to control the intake quantity more suitably is provided.

Abstract: An internal combustion engine is capable of changing a compression ratio according to an output torque. A motor is connected with an output shaft of the internal combustion engine to transmit torque to and from the output shaft. The internal combustion engine detects a torque demand required to the internal combustion engine. When the torque demand exceeds a threshold torque, which is set in advance for changeover of setting of the compression ratio in the internal combustion engine, the motor is controlled to output a torque to the output shaft. The torque output from the motor restricts the output torque of the internal combustion engine to be not greater than the threshold torque. Such control effectively prevents frequent changeover of the setting of the compression ratio in the internal combustion engine. This arrangement desirably saves energy required for the frequent changeover of the compression ratio and thus enhances the total efficiency of the internal combustion engine.

Abstract: A control system of an internal combustion engine includes a timing changing unit that changes opening and closing timing of an intake valve relative to rotation of an output shaft of the engine, a working angle changing unit that changes a working angle of the intake valve, a throttle mechanism including a throttle valve provided in an intake passage of the engine and an actuator that is operable to open and close the throttle valve, and an intake air quantity control unit that controls the timing changing unit, the working angle changing unit and the throttle mechanism so as to control an intake air quantity of the engine to a target intake air quantity. The control system detects a failure of at least one of the timing changing unit, the working angle changing unit and the throttle mechanism, and, upon detection of a failure, executes a selected one of difference fail-safe control processes corresponding to different forms of failures, depending upon the form of the detected failure.

Abstract: An engine control system for a compression ignition engine employs a microprocessor-based controller that detects engine operation in a speed range previously determined to be undesirable, and responding to the detection by changing operation of the engine. In the preferred embodiment, the controller commands a parameter for adjusting engine operation to reach a different speed outside of first and second thresholds defining the undesirable range in a time period subsequent to the detection.

Abstract: A gaseous fuel analyzer having a flow through chamber equipped with sound producing means at one end and sound receiving means at the other for measuring an acoustic property of fuel flowing through the chamber and for numerically relating the acoustic property to the combustion character of the fuel.

Abstract: An engine including an engine block, and spark timing structure for advancing and retarding spark timing between a minimum spark advance and a maximum spark advance, the spark timing structure including a spark timing link comprising a stop and being movable between a minimum advance position and a maximum advance position spaced in one direction from the minimum advance position, the spark timing structure also including a spark timing lever including a surface and being movable between a first position wherein the surface is spaced from the stop when the link is in the minimum advance position, a second position wherein the surface engages the stop when the link is in the minimum advance position so as to provide common movement of the link and the spark timing lever in response to further movement of the lever in the one direction, and a third position wherein the link is in the maximum advance position when the surface engages the stop.

Abstract: A control system for a vehicle engine comprises a first detecting device for detecting a controlled variable on an accelerator, an engine ouput adjusting device, such as a throttle valve, a second detecting device for detecting a situation wherein a vehicle employing therein the vehicle engine is in a travelling condition of traffic jam, and a control device for controlling the engine output adjusting device to cause the vehicle engine to vary its engine output with a predetermined rate of variation in the engine output to the controlled variable on the accelerator when the situation wherein the vehicle is in the travelling condition of traffic jam is not detected by the second detecting device and with a diminished rate of variation in the engine output to the controlled variable on the accelerator when the situation wherein the vehicle is in the travelling condition of traffic jam is detected by said second detecting device so as to have the engine output adjusted in accordance with the controlled variable

Abstract: A throttle control system for a vehicle of the type including a throttle body and a throttle valve mounted within the throttle body and controlling the delivery of fuel and/or air to the engine of the vehicle.

Abstract: A method of controlling an engine mounted on a construction vehicle comprising the steps of reducing the rotation of the engine to a primary number of revolutions per minute, which is in the vicinity of the rated number of revolutions per minute of the engine under earth moving operation conditions, immediately after all operating levers associated with all of the control valves for turning the vehicle body, for actuating work implements and for running of the vehicle are shifted to their neutral positions, maintaining the engine under such a low speed running condition for a predetermined period of time, and then reducing further the rotation of the engine to a lower, secondary number of revolutions per minute which corresponds to the number of revolutions per minute under idle running conditions thereby achieving reduction in fuel consumption and level of noise generated by the engine.

Abstract: A carburetor having a throttle valve and throttle shaft is shown provided with a throttle shaft lever which has a U-shaped portion carrying a linkage connecting member effective for connection to associated throttle actuating linkage; a sleeve-like spacer is situated about the connecting member and between the legs of the U-shaped portion as to add rigidity thereto.

Abstract: An intake air throttling system for a diesel engine comprising an air intake passage. The system includes a throttling valve mounted in the air intake passage so as to selectively throttle air flow through it. This throttling valve can be positioned to at least a first position in which it substantially fully closes the air intake passage, a second position in which it partly throttles the air intake passage to a substantial extent but does not fully close it, and a third position in which it does not throttle the air intake passage to any substantial extent. The throttling valve is controlled by a control system, which positions it to the first position when the engine is being stopped, which positions it to the second position when the engine is being idled, and which positions it to the third position when the engine is being operated in non idling load bearing operational condition.