Abstract: A two-cycle action cam having two protruding parts 1a and 1b and a four-cycle action cam 3 having one protruding part 3a are selectively used by a cam change mechanism 46i. The two-cycle action cam 1 effects opening of the inlet and exhaust valves once per revolution of the crankshaft and the four-cycle action cam 3 effects opening of the inlet and exhaust valves once per two revolutions of the crankshaft. The four-cycle action is selected when the engine is in the low revolving speed and running at a low load and the two-cycle action is otherwise selected.

Abstract: The EGR controller 1 controls the EGR actions wherein exhaust gas from the cylinder cut-off engine 3 which can change over the running condition between the all-cylinder run and the cut-off-cylinder is recirculated to the induction. The EGR controller 1 comprises an EGR control valve 6 for opening and closing the EGR pipe 13, a water temperature sensor 5 for detecting cooling water temperature TW and an ECU 2, and the ECU 2 controls the EGR actions so as tobe executed if the cooling water temperature TW is higher (determined as “Yes” at Step 10) than the upper limit value TWE1H while at the all-cylinder run (determined as “No” at Step 2) or if the cooling water temperature TW is higher than the lower limit value TWE1L while at the cut-off-cylinder run (determined as “Yes” at Step 2).

Abstract: In an apparatus for controlling a multi-cylinder internal combustion engine with partial cylinder switch-off mechanism which is switchable between an all-cylinder operation mode in which all cylinders are operated and a partial-cylinder operation mode in which operation of partial cylinders is suspended, the operation of intake valves and exhaust valves is suspended or resumed in a predetermined order with respect to all of the suspended cylinders irrespective of a rotational frequency of the engine. There are provided a solenoid valve on an intake side and a solenoid valve on an exhaust side for switching input hydraulic pressures for hydraulically operated switching devices respectively on the intake side and on the exhaust side between the driving state and the drive-free state. At the time of switching the operation, one of the solenoid valves on the intake side and the exhaust side is driven in advance. The subsequent number of rotations of a crankshaft is counted.

Abstract: A high probability of detecting an erroneous misfire occurs when combustion becomes unstable during jolt control. Therefore, during jolt control the reliability of the misfire detection system is degraded. As a result, the misfire detection system is inactivated during jolt control by discontinuing the misfire detection, or by deliberately deeming no misfire has occurred if jolt control has occurred. Alternatively, the misfire detection sensitivity is masked during jolt control.

Abstract: A spark plug cap covering the terminal of a spark plug for an internal combustion engine, made up of an insulative cap body, an ignition coil unit case housing the coil and having a terminal for the ignition coil, a first conductive shaft housed in the insulative cap body for carrying an ignition voltage produced by the ignition coil to the spark plug terminal, and a second conductor located around the first conductor keeping a predetermined distance therefrom separated by the insulative material of the cap body such that a capacitor is formed between the first and second conductors for detecting the ignition voltage.

Abstract: An ignition coil unit for an internal combustion engine for containing an ignition voltage detective capacitor for misfire discrimination, including a core, a primary and a secondary coil wound around the core, and a case housing the core and the primary and secondary coils which is filled with an insulative material. In this unit, a first conductive electrode plate is placed in the case and electrically connected with the output of the secondary coil, and a second conductive electrode plate is also placed in the case in parallel with the first conductive electrode plate while maintaining a predetermined distance therefrom. An insulator is interposed between the first and second conductive electrode plates forming a capacitor that uses the insulator as the dielectric.

Abstract: A device according to an aspect of the invention detects abnormality of spark plugs of an internal combustion engine. A value related to electric resistance across a gap between electrodes of each spark plug is measured. Next, it is determined whether or not the measured value, related to the electric resistance, assumes a value indicating that the electric resistance is below a predetermined value, when the engine is determined to be in a non-combustive state. The spark plug is determined to be abnormal when it is determined that the measured value, related to the electric resistance, assumes the value indicating that the electric resistance is below the predetermined value. A misfire-detecting system according to another aspect of the invention incorporates the above device.

Abstract: A method of manufacturing a spark plug cap covering a spark plug for an internal combustion engine, equipped with an ignition voltage detective capacitor having a first conductor housed in a cap body for carrying an ignition voltage produced by an ignition coil to the spark plug and a second conductor located keeping a predetermined distance from the first conductor while sandwiching an insulative material such that the capacitor is formed between the first and second conductors for detecting the ignition voltage. The method comprises separately fabricating said insulative body and a member from the insulative material embedding said second conductor therein and fixing the member at said insulative body such that said detective capacitor is formed. The second conductor may be formed in the shape of a plate to be wound around the cap body.

Abstract: A fuel supply control system which controls an amount of fuel supplied to an internal combustion engine. An ECU detects a value related to an amount of combustion ions generated within cylinders. The detected value is compared with a predetermined value, and the amount of fuel supplied to the engine is corrected based upon the comparison result, when the engine is in a transient operating condition, such as acceleration and deceleration, whereby the responsiveness of the air-fuel ratio feedback control is enhanced to improve drivability and exhaust emission characteristics.

Abstract: A misfire-detecting system detects a misfire occurring in an internal combustion engine. A value of sparking voltage for discharging a spark plug of the engine is detected. The detected value of the sparking voltage is compared with a first predetermined value. A degree to which the detected value of the sparking voltage exceeds the first predetermined value is measured. The measured degree is compared with a second predetermined value. It is determined based upon results of the latter comparison whether or not a misfire occurred in the engine. According to a first aspect of the invention, the second predetermined reference value is set based upon detected values of operating parameters of the engine. According to a second aspect of the invention, the determination of occurrence of a misfire is inhibited when the engine is in a predetermined operating condition.

Abstract: An engine control system comprising a variable valve actuating mechanism for an engine which may consists of a mechanism capable of varying valve timing, a variable capacity supercharger which may consists of a turbocharger provided with moveable vanes for varying a cross sectional area of an exhaust gas passage leading to a turbine wheel, and a control unit for controlling a valve actuating operation of the valve actuating mechanism and a capacity varying operation of the variable capacity supercharger. The capacity of the supercharger is controlled by taking into account the operating conditions of the valve actuating mechanism. Thus, the control unit is capable of achieving a precise and prompt control action, and, by appropriately determining the control plan, it is possible to increase the maximum output of the engine and/or to reduce strain on the engine.

Abstract: A driving wheel slip control system for a vehicle detects an excessive slip state of at least one of the driving wheels of the vehicle and reduces engine output when the excessive slip state is detected, by repeating alternate fuel cut and fuel supply such that fuel supply is stopped for a first predetermined time period, and a second predetermined time period. During the second predetermined time period the engine is supplied with an amount of fuel smaller than one required for an operating condition of the engine in the excessive slip state. If the excessive slip state has a greater variation in magnitude than a certain value, fuel supply is continuously effected for a third predetermined time period longer than the first predetermined time period or all the time during the excessive slip state.

Abstract: A method of detecting abnormality in a fuel supply system of an internal combustion engine. An amount of fuel supplied to the engine is controlled in a feedback manner based on an air-fuel ratio correction coefficient set in response to an output signal from at least one exhaust gas component concentration sensor. The method comprises the steps of (1) calculating an abnormality determination value based on the air-fuel ratio correction coefficient, (2) calculating a learned average value of the air-fuel ratio correction coefficient, (3) renewing the abnormality determination value when the calculated learned average value of the air-fuel ratio correction coefficient falls outside a first predetermined range defined based upon the abnormality determination coefficient, and (4) determining that the fuel supply system is abnormal when the renewed value of the abnormality determination value falls outside a second predetermined range defined by predetermined upper and lower limit values.

Abstract: A driving wheel slip control system installed in a vehicle and having abnormality-detecting and failsafe functions. The system includes a slip status signal-generating device for generating a slip status signal indicative of whether or not the driving wheels of the vehicle are in a predetermined slip state, and a slip level signal-generating device for generating a slip level signal indicative of a degree of slip of the driving wheels. If a logical relationship between the slip status signal and the slip level signal is abnormal, and if the prime mover for driving the driving wheels is not accelerating and at the same time the slip level signal indicates the predetermined slip state, the slip level signal is determined to be abnormal. If an abnormality is detected during driving wheel slip control, an amount of reduction in output of the driving wheels is set to a predetermined amount to thereby continue driving wheel slip control, until the prime mover enters an operating condition other than acceleration.

Abstract: A system for controlling a boost pressure in an internal combustion engine is equipped with a turbocharger. Engine operation is divided into three regions based on an engine speed with respect to an engine load. Throughout the regions, a target boost pressure is predetermined to be considerably lower than a level at which knock frequently occurs. In the region where the engine speed and load are relatively high, the target boost pressure is gradually raised until knock occurs. When knock occurs, the target boost pressure is fixed at a value slightly lower than the value at which knock has occurred and thereafter the boost pressure is controlled to the fixed target pressure.

Abstract: A driving wheel slip control system in which cutoff of fuel supply to a cylinder to be controlled in respect of fuel supply when it has been determined that fuel cut is required, for the first time after a predetermined condition for carrying out driving wheel slip control was satisfied, is inhibited, when the cylinder belongs to the rear bank of cylinders of an internal combustion engine.

Abstract: In a cooling control system for controlling cooling of an engine room of an engine, a water pump and/or cooling fans are arranged within the engine room to cool same, and electric motors electrically drive the water pump and cooling fans. A control unit compares a temperature of the engine detected by a temperature sensor with a plurality of different predetermined values, and based upon results of the comparison, controls the electric motors for driving the cooling fans in such a manner that as the detected temperature is higher, the flow rate of cooling air flowing in the engine room is larger. The control unit is operable when abnormality occurs in sensors for sensing operating conditions of the engine, for operating the electric motors to drive the water pump and cooling fans. Alternatively, an analog circuit is operable when abnormality occurs in the control unit, for operating the electric motors to drive the water pump and the cooling fans.

Abstract: A cooling control system for an internal combustion engine equipped with a supercharger. The control system includes an electrically-driven pump for circulating coolant for cooling the supercharger, and an electrically-driven fan arranged in an engine room. The cooling control system controls the operation of the electrically-driven pump and the operation of the electrically-driven fan, based on an output from a sensor for detecting stoppage of the engine as well as on operation of a timer for counting a predetermined time period. The cooling control system controls, during operation of the engine, the operation of the electrically-driven pump and the operation of the electrically-driven fan, based on an output from a sensor or sensors for detecting operating conditions of the engine.

Abstract: A system for controlling the idling rotational speed of an internal combustion engine controls a control valve for adjusting the opening area of an intake air passage bypassing a throttle valve after cranking of the engine, by the use of control terms including a differential term which is based on a variation in the engine rotational speed and is set and held at zero before a predetermined time period elapses after completion of cranking of the engine.

Abstract: An electronically-controlled fuel injection system for internal combustion engines. When the engine is in an accelerating condition, an amount of fuel supplied to the engine is increased by means of an incremental value. It is discriminated whether or not a predetermined time period has elapsed from the time the rotational speed of the engine increased above a predetermined value, or from the time gear shifting was completed, while the engine is in the accelerating condition. The incremental value is limited to a predetermined upper limit if the former exceeds the latter before the lapse of the predetermined time period, whereby sudden increase in the engine rotational speed can be prevented.