Abstract: A crank angle sensor comprises a rotor plate formed with first slits for detecting a first cylinder angular position, second slits for a second cylinder angular position, and a third slit for detecting an angular position of a specified cylinder. The first slits are equi-angularly distant one after another and arranged within a predetermined annular band within the rotor plate, and the second slits are equi-angularly distant one after another and arranged within the predetermined annular band. Each of the first slits is located adjacent to the corresponding one of the second slits.

Abstract: A pressure regulator has a spool valve positioned by a linear motor to control flow through a spill passage from a fuel inlet to a fuel outlet and thereby control the fuel pressure in the inlet as a function of the current in the linear motor, a piston subjected to the pressure in the fuel inlet and defining a variable orifice adapted to create a reference pressure at a desired differential from the pressure in the fuel inlet, a diaphragm subjected to the reference pressure and the pressure in the air inlet, and a valve positioned by the diaphragm to control flow from the air inlet to the air outlet whereby the pressure in the air inlet is maintained at a desired differential below the pressure in the fuel inlet.

Abstract: A throttle stop assembly for an internal combustion engine is provided to return the throttle shaft to an idle position from a full throttle position in the event a loose throttle level mounting bolt occurs. The throttle stop assembly is designed to for the throttle shaft stop element from the full throttle position to the idle position if the throttle lever mounting bolt assembly fails, thereby preventing the engine from continuing to run in an advanced throttle condition. The stop assembly of the present invention includes a spring-biased piston contained within a threaded, hollow shaft. The spring biased piston has no effect on throttle shaft position except when the normal throttle shaft operating system fails in which case the spring biased piston will cause the throttle shaft to return to its idle position.

Abstract: A fuel control apparatus is provided for an engine which is primarily used for a vehicle so as to permit the changing of a valve opening-closing timing and/or a valve lift amount for a valve on at least one of an intake side and an exhaust side. Accordingly, to the present invention, the fuel supply to the engine can thus be properly adjusted or corrected in each of the operation ranges with different valve timings so as to improve engine drivability.

Abstract: For controlling supply of electric power to a heater for an oxygen sensor for detecting oxygen in an exhaust system of an internal combustion engine so as to maintain the electric resistance of the heater to a target value therefor, the target value is corrected based upon detection of the amount of electric power supplied to the heater so that difference between the detected amount of electric power supplied to the heater and a standard value therefor is cancelled.

Abstract: An emergency ignition system for motor vehicles comprises a high-voltage coil having an input circuit connectible to the vehicle battery and an output circuit connectible to the vehicle distributor for applying high-voltage pulses. The input circuit includes an oscillator generating periodic pulses, and a switch controlled by the oscillator for periodically interrupting the input circuit to the coil and thereby causing the coil to generate high-voltage pulses to be applied to the vehicle distributor. The input circuit further includes a control circuit connectible to the vehicle battery and comprising a voltage-drop sensor for sensing a predetermined voltage drop at the output of the vehicle battery caused by the load thereon when starting the engine, and for producing an enabling signal in response to the predetermined voltage drop to enable the oscillator to output pulses to the switch for periodically interrupting the input circuit to the coil.

Abstract: A protective case (13) for a vehicle ignition system covers both the ignition coil (5), an electronic control device (6), and the terminals (11) and connecting conductors (12) therebetween. The preferred material is plastic, with an electromagnetically conducting coating for screening against incoming and outing electromagnetic noise. Thus, protection is provided against mechanical, chemical, and electromagnetic environmental influences. The case is dimensioned to snap over and seal respective edges of the electronic control device (6), the ignition coil (5) and its core (8), the electrical terminals (11), and the interconnecting conductors (12). The case is bifurcated along an access slit (16) which is secured in a normally closed position by knob (15) which press-fits into a mating hole on the other side of the slit. Two sides of the case have curved ridges or dimples which provide flexibility to hinge the case open for insertion of the ignition coil (5) and electronic control device (6).

Abstract: A method of determining the activation of an exhaust gas ingredient-concentration sensor for use in an internal combustion engine. The air-fuel ratio of a mixture is controlled in a feedback manner by the use of a coefficient varying with an output of the sensor during engine operation in an air-fuel ratio feedback control region. The activation of the sensor is determined based on the output of the sensor. When the engine has shifted from the air-fuel ratio feedback control region to a predetermined decelerating region, calculated is an average value of values of the coefficient obtained by the feedback control immediately before the shifting. The air-fuel ratio of the mixture is leaned by the use of the average value thus calculated. It is determined whether or not the sensor is activated when the air-fuel ratio has thus been leaned.

Abstract: Control of spark timing of an ignition system for an internal combustion engine uses a feedback correction signal which is a function of back EMF generated in the primary winding of an ignition coil in response to current change in the secondary winding of the ignition coil due to spark breakdown.

Abstract: A fail safe system for a cylinder pressure sensor is used for a spark ignition timing control system which calculates a physical quantity for combustion energy within the combustion chamber of an engine cylinder of an internal combustion engine and corrects the spark ignition timing on the basis of the physical quantity. The fail safe system sets a running average of a statistical dispersion of the physical quantity to a predetermined greater value when a specific driving condition, i.e. a high engine load and high engine speed condition is initially determined, and thereafter compares the running average with a predetermined value when the specific driving condition is detected again to detect abnormality of the cylinder pressure sensor.