Abstract: An idle speed control apparatus includes an electronic control unit connected to sensors and switches for detecting the on-off states of an air conditioner and other devices, throttle opening, engine speed, etc. The electronic control unit selectively drives fuel injection valves for adjusting the injection quantity, air bypass valve for adjusting the suction rate, and/or EGR valve for adjusting the exhaust gas recirculation rate in accordance with an engine load detected by the sensors and switches, thereby selectively executing air-fuel ratio adjustment, suction rate adjustment, and/or exhaust gas recirculation rate adjustment as required, giving priority to the air-fuel ratio adjustment and suction rate adjustment in the order named. Thus, idle speed control to cope with engine load fluctuations can be carried out with stability.

Abstract: A clock signal hull detector includes a signal level monitor for detecting an extraordinary condition in which the clock signal to be monitored is stuck at either a high level or a low level and a turning point number monitor for detecting an extraordinary condition in which the clock signal changes its level between the high and low levels with high frequency. The outputs of the signal level monitor and the turning point number monitor are fed to a fault judgment portion, which delivers an output according to the extraordinary conditions. The output of the fault judgment portion is then fed to a counting portion at which a fault judgment signal is fed to its output when its input signal is counted to a predetermined value or above.

Abstract: A control system is provided for an internal combustion engine which can stop the supply of fuel to some of its cylinders to perform part cylinder operation in a particular state of operation, The control system promptly stabilizes the engine speed after effecting switching between full cylinder operation and part cylinder operation and also stabilizes an idle speed with good responsibility by correcting the ignition timing. The control system calculates basic ignition timing, the difference between a smoothed engine speed and the engine speed, and an ignition timing correction amount corresponding to the difference at least in the course of the idling. The control system further includes an ignition timing correction control system for controlling the manner of operation of the calculation of the ignition timing correction amount upon at least one of the switching between the full cylinder operation and the part cylinder operation, and the part cylinder operation.

Abstract: A valve moving control apparatus for an internal combustion engine comprising a control device for switching at least one valve by controlling a driving condition of an intake/exhaust valve, a load detecting device, a switch control device for outputting a switch signal to the control device, and a gear shift detecting device. The gear shift detecting device detects whether a gear is shifted to a relatively low gear in a gearbox. If the gear is shifted to a relatively low gear, a switching point for switching an actuation of the valve is shifted to a low load side in order to reduce torque shock caused by switching.

Abstract: The present invention relates to an automotive vehicle engine having controls for switching between a whole cylinder working mode and a partial cylinder non-working mode by making a valve motion arrangement operated in the intake and exhaust process. The automotive vehicle engine comprises-a revolution sensor, a boost pressure sensor, an ignition driving apparatus and a controlling apparatus for controlling the cylinder suspending mechanism and the ignition driving apparatus. The partial cylinder non-working mode or the all cylinder working mode is determined on the basis of the revolution speed "Ne" and the boost pressure data "Pb".

Abstract: Disclosed is an automobile engine which has different ranges for the partial cylinder operation mode depending upon whether or not the engine is idling. The partial cylinder operation mode is selectable in different operation ranges in response to operating status of an air-conditioner, a power steering switch or a throttle opening sensor. Thus, the engine can reliably assume the partial cylinder operation mode in a wide operation range without stall, thereby accomplishing fuel saving.

Abstract: In a fuel blending ratio detecting method, a first blending ratio of the methanol in the fuel supplied to an internal combustion engine is detected by a blending ratio sensor; an air/fuel ratio feedback compensation coefficient computed on the basis of an output of an O.sub.2 sensor is used to compute a feedback learned value, and the current blending ratio compensation coefficient is multiplied by this value to compute the next blending ratio compensation coefficient so as to obtain a second blending ratio; the current blending ratio compensation coefficient is multiplied by a peak mean value of the computed feedback compensation coefficient to compute the next blending ratio compensation coefficient so as to obtain a third blending ratio; and the first, second or third blending ratio is selected according to the operating conditions of the internal combustion engine.

Abstract: In an operation control method of an engine using a mixed fuel of a mixture of a plurality of fuels having different properties, operation condition of the engine being controlled according to a detection signal from a fuel blend ratio detector for detecting the blend ratio of the plurality of fuels in the mixed fuel, and when a malfunction occurs in the detection by the fuel blend ratio detector, the engine is provided with blend ratio storage for storing a plurality of emergency blend ratios for ignition timing control and for air fuel ratio control, and operation condition of the engine is controlled according to the plurality of emergency blend ratios.

Abstract: A method includes a step of calculating an estimated blending ratio of a mixed fuel supplied to a combustion chamber of an internal combustion engine and a following equation is effected in this step to derive the estimated blending ratio:B(t)=k*B(t-1)+(1-k)*Bs(t-n)where t is an integer,n is a first delay coefficient set according to an operation parameter and a type of the engine,B(t-1) is an estimated blending ratio derived in the preceding cycle,Bs(t-n) is a blending ratio obtained by use of said blending ratio sensor in a cycle which was effected n cycles before the current cycle, andk is a second delay coefficient set according to a operation parameter and the type of the engine.

Abstract: In a fuel blending ratio detecting method, a first blending ratio of the methanol in the fuel supplied to an internal combustion engine is detected by a blending ratio sensor; an air/fuel ratio feedback compensation coefficient computed on the basis of an output of an O.sub.2 sensor is used to compute a feedback learned value, and the current blending ratio compensation coefficient is multiplied by this value to compute the next blending ratio compensation coefficient so as to obtain a second blending ratio; the current blending ratio compensation coefficient is multiplied by a peak mean value of the computed feedback compensation coefficient to compute the next blending ratio compensation coefficient so as to obtain a third blending ratio; and the first, second or third blending ratio is selected according to the operating conditions of the internal combustion engine.

Abstract: A fuel blending ratio detecting method is provided which includes a feedback computing compensation coefficient K.sub.FB on the basis of an air/fuel ratio responsive output V.sub.o of an O.sub.2 sensor, computing a feedback learned value K.sub.LRN on the basis of the feedback compensation coefficient K.sub.FB at intervals of a predetermined period, and multiplying the current blending ratio compensation coefficient K.sub.B by this feedback learned value K.sub.LRN to compute the next blending ratio compensation coefficient K.sub.B. Thus, the quantity of fuel supplied to the internal combustion engine can be always controlled accurately on the basis of the computed blending ratio compensation coefficient.

Abstract: A fuel blending ratio detecting method is provided wherein a feedback compensation coefficient K.sub.FB is computed on the basis of an air/fuel ratio responsive output V.sub.o of an O.sub.2 sensor, and a current blending ratio compensation coefficient K.sub.B is multiplied by a peak mean value K.sub.PEAK of the current and preceding peak values of the computed feedback compensation coefficient K.sub.FB to compute the next blending ratio compensation coefficient K.sub.B. Thus, the quantity of fuel supplied to the internal combustion engine can be always controlled accurately on the basis of the computed blending ratio compensation coefficient.

Abstract: A fuel blending ratio detecting method computes a control blending ratio on the basis of blending ratio information generated from a blending ratio sensor or air/fuel ratio information generated from an O.sub.2 sensor, and when the engine is stopped, the control blending ratio detected at that time is stored in a backup memory as a memory blending ratio. At the time of re-starting the engine, the memory blending ratio can be used as the control blending ratio B for a predetermined limited period.

Abstract: An air-fuel ratio feedback control method for a multi-fuel internal combustion engine using a dual O.sub.2 sensor system is provided, in which the concentration of oxygen in exhaust gas on the upstream side of an exhaust gas purifier is detected, a value corresponding to the detected oxygen concentration is compared with a first target value, and the air-fuel ratio is feedback-controlled in accordance with the result of the comparison. The mixture ratio of at least two fuels is detected, and a second target value is set in accordance with the detected fuel mixture ratio. On the other hand, the concentration of oxygen in the exhaust gas on the downstream side of the exhaust gas purifier is detected, and a value corresponding to the detected downstream-side oxygen concentration is obtained. The first target value is corrected in accordance with the difference between the obtained value and the second target value.

Abstract: Provided according to the present invention is a vehicular engine cooling apparatus comprising cooling fan means for cooling at least one of an engine and an environment of the engine, the engine being operated with use of any of two or more different fuels and a mixed fuel formed of a combination of the different fuels. This apparatus further comprises a mixture ratio sensor for detecting the mixture ratio of the two or more different fuels, and a controller for actuating the cooling fan means in accordance with the fuel mixture ratio detected by the mixture ratio sensor, after the engine is stopped. Preferably, the cooling fan is operated only during a predetermined operating time set in accordance with the fuel mixture ratio and the temperature of at least one of the engine and the environment of the engine.

Abstract: In an engine using fuel mixture of gasoline and methanol, the present control system compensates a detection value of a blend ratio sensor with a detection value of a knock sensor, or causes trouble detecting means to detect a failure of the blend ratio sensor and memories the blend ratio immediately before the failure as an assumed blend ratio and compensates the stored value with the detection value of the knock sensor, whereby the engine control is executed based on the control blend ratio and the ignition timing acquired through the compensation.