Abstract: The internal combustion engine (1) has a throttle (23) for controlling an intake air amount and performs start-up through cranking. The starter switch (36) detects cranking initiation, and the crank angle sensor (33, 34) detects the number of revolutions of the engine. The controller (31) drives the throttle (23) in a closed position along with the cranking initiation. The controller (31) can obtain both the intake negative pressure for promoting vaporization of fuel and the intake air amount necessary to maintain the idle rotation speed by counting the number of strokes or the number of revolutions of the internal combustion engine (1) from the cranking initiation and opening the throttle (23) from the closed position as the count number reaches a predetermined number.

Abstract: The internal combustion engine (1) has a throttle (23) for controlling an intake air amount and performs start-up through cranking. As the cranking is initiated, an atmospheric pressure is detected and an initial opening is set accordingly. The controller (31) controls the throttle (23) to the initial opening when the cranking is initiated, and controls the throttle to start to increase the throttle opening from the initial opening at a predetermined timing after the cranking initiation. By setting the initial opening based on one or both of the atmospheric pressure and the temperature at the time of cranking initiation, the intake negative pressure and the intake air amount are optimized.

Abstract: The internal combustion engine (1) has a throttle (23) for controlling an intake air amount and performs start-up through cranking. As the cranking is initiated, an atmospheric pressure is detected and an initial opening is set accordingly. The controller (31) controls the throttle (23) to the initial opening when the cranking is initiated, and controls the throttle to start to increase the throttle opening from the initial opening at a predetermined timing after the cranking initiation. By setting the initial opening based on one or both of the atmospheric pressure and the temperature at the time of cranking initiation, the intake negative pressure and the intake air amount are optimized.

Abstract: The internal combustion engine (1) has a throttle (23) for controlling an intake air amount and performs start-up through cranking. The starter switch (36) detects cranking initiation, and the crank angle sensor (33, 34) detects the number of revolutions of the engine. The controller (31) drives the throttle (23) in a closed position along with the cranking initiation. The controller (31) can obtain both the intake negative pressure for promoting vaporization of fuel and the intake air amount necessary to maintain the idle rotation speed by counting the number of strokes or the number of revolutions of the internal combustion engine (1) from the cranking initiation and opening the throttle (23) from the closed position as the count number reaches a predetermined number.

Abstract: A reference position of a camshaft used in detection of a rotational phase of the camshaft relative to an engine crankshaft during the feedback control operation of a variable valve-timing controlling system adjustably changing the valve-timing of the engine, is learned in such a manner that result of detection of the rotational phase is smoothed more effectively than when the feedback control operation of the variable valve-timing controlling system is carried out, so as absorb unequal spaces among detection subjects of the cam sensor arranged around the camshaft.

Abstract: In a variable valve timing system for an internal combustion engine, a soft-landing revertive control that an electromagnetic brake is de-energized and then an angular position of a camshaft relative to a crankshaft returns to an initial position is performed by a combination of a feedback control and a feedforward control. During the revertive control, the feedback control is executed in such a manner as to temporarily halt the angular phase of the camshaft at a predetermined position, which is phase-changed by a predetermined phase angle from the initial position. After the feedback control, the operating mode is switched to a feedforward control, so as to return the angular phase of the camshaft from the predetermined position to the initial position by changing a controlled quantity or a control-signal duty cycle value for the electromagnetic brake with a predetermined time rate of change.

Abstract: In a variable valve timing system for an internal combustion engine, a soft-landing revertive control that an electromagnetic brake is de-energized and then an angular position of a camshaft relative to a crankshaft returns to an initial position is performed by a combination of a feedback control and a feedforward control. During the revertive control, the feedback control is executed in such a manner as to temporarily halt the angular phase of the camshaft at a predetermined position, which is phase-changed by a predetermined phase angle from the initial position. After the feedback control, the operating mode is switched to a feedforward control, so as to return the angular phase of the camshaft from the predetermined position to the initial position by changing a controlled quantity or a control-signal duty cycle value for the electromagnetic brake with a predetermined time rate of change.

Abstract: A reference position of a camshaft used in detection of a rotational phase of the camshaft relative to an engine crankshaft during the feedback control operation of a variable valve-timing controlling system adjustably changing the valve-timing of the engine, is learned in such a manner that result of detection of the rotational phase is smoothed more effectively than when the feedback control operation of the variable valve-timing controlling system is carried out, so as absorb unequal spaces among detection subjects of the cam sensor arranged around the camshaft.

Abstract: An exhaust gas recirculation control system for an internal combustion engine comprises sensors detecting operating conditions of the engine, an air-flow meter detecting an actual intake-air flow rate, an exhaust-gas-recirculation passage connecting an exhaust manifold with an intake manifold, an exhaust-gas-recirculation control valve device disposed in the exhaust-gas-recirculation passage for regulating an EGR rate. An electronic control unit is electronically connected to the sensors and the exhaust-gas-recirculation control valve device.

Abstract: A fuel injection timing control system for a diesel fuel injection pump with a duty-cycle controlled electromagnetic solenoid valve associated with an injection-timing-control timer piston to change a timer-piston axial position or a set position of a pump plunger in response to a duty cycle of the electromagnetic solenoid valve, comprises a control unit for transiently permitting the entry of a duty cycle of the electromagnetic solenoid valve into a predetermined dead-zone for a predetermined period of time during a fuel injection timing closed-loop control in which an actual injection timing is feed-back controlled toward a target injection timing. In addition, the control unit limits the duty cycle of the electromagnetic solenoid valve to a predetermined limiting value as soon as the predetermined time period has been elapsed, during the fuel injection timing closed-loop control.

Abstract: The setting of a continuously variable transmission to a neutral range is detected as a neutral signal. A delayed signal which follows a change of this neutral signal is generated with a delay, and when this delayed signal indicates the neutral range, a target idle rotation speed of a diesel engine is increased. An exhaust throttle is provided to allow the exhaust pressure of an engine to rise in order to raise heating efficiency in the passenger compartment when a vehicle is at rest. By avoiding a delay period from the change of the neutral signal to a change in the delayed signal, torque shock due to the opening or closing of the exhaust throttle is reduced.

Abstract: An engine control system reduces thermal deterioration of a torque converter. Maximum torque down control is provided, using simple processing and a minimum number of required signals, to reduce thermal deterioration. A maximum fuel injection amount QFULL is reduced when vehicle speed is less than a predetermined value that is close to zero, thereby lowering maximum engine torque. Also, the presence or absence of an abnormal vehicle speed sensor is diagnosed and maximum engine torque is also lowered during occurrence of an abnormality.

Abstract: A testing apparatus for a combustible charge intake system of an internal combustion engine, including a throttle position sensor and a throttle switch respectively coupled with a throttle valve, an accelerator switch coupled with an accelerator pedal, and a control unit operatively coupled with the switches. The control unit is operative to determine that the throttle valve has failed to operate normally when the throttle switch fails to shift to its predetermined state after the accelerator switch has shifted to its predetermined state. The control unit is operative to determine that the accelerator switch fails to operate normally in response to the control unit determining that the accelerator switch has failed to take the predetermined state thereof after the throttle switch has been in the predetermined state thereof.

Abstract: In an apparatus and method for diagnosing presence of absence of a (wire) breakage in electromagnetic coil means such as a duty ratio controlled solenoid or at least one exciting coil portion between an end of a stator coil and a tap of a stepping motor, a checking circuitry is connected to a junction between the electromagnetic coil means and a driving transistor (switching element) to provide a checking pulse signal which provides a particular level only when an input duty ratio (pulsewidth modulated) signal is at a predetermined non-actuation (low) level and no breakage in the electromagnetic coil means occurs. In the embodiment, the checking pulse signal is sampled at a predetermined sampling period which is shorter than the period of the pulsewidth modulated signal. A historical memory in a sub CPU records (stores) a history of the sampled checking pulse signal.