Abstract: An apparatus for detecting a malfunction in an evaporated fuel purge system for use in an internal combustion engine. The apparatus includes a vapor passage connecting a fuel tank to a canister for feeding fuel vapor from the fuel tank into the canister, a purge passage connecting the canister to an intake passage of the engine for feeding the fuel vapor adsorbed in an adsorbent in the canister into the intake passage, an air inlet passage connecting an air inlet port of the canister to the atmosphere, a first control valve provided for controlling a flow of the adsorbed fuel vapor from the canister to the intake passage, a pressure sensor provided for outputting a signal indicative of a pressure in the air inlet passage, a second control valve for controlling a flow of external air fed into the vapor passage from the air inlet port of the canister, and a malfunction detection part responsive to the signal outputted by the pressure sensor for detecting a malfunction in the evaporated fuel purge system.

Abstract: A flexible header mounting for an engine mounted fuel filter includes structure for dependingly engaging a fuel filter and its associated plumbing and a planar base member by means of which the header is mounted to the engine supporting structure. Flexible engagement of the base member to the engine is accomplished by means of bolts, each of which has a compression spring mounted thereon over the shaft thereof, between the base member and the bolt head. The free threaded end of the bolt extends through a bore drilled into the base member and engages within a threaded bore in the engine housing. The distance between a center point of the bolt and a forward edge of the base plate is as large as possible while the distance between the center point of the bolt and the rear edge is as small as possible, creating a joint wherein the header may pivot rearwardly upon impact but will be unable to pivot forwardly under severe deceleration.

Abstract: An electromechanical/hydraulic assembly controlled by circuit board, acting on an engine throttle so as to allow for remote control and engine fault protection. An idle solenoid pushes and slides a captive throttle rod through a linear translation bracket so as to move engine throttle to idle position for fixed time upon starting. Engine oil pressure flows through a controlled check valve in reduced flow direction into a solenoid valve and then into a hydraulic cylinder to gradually advance indirectly attached throttle to operating position. Hydraulic cylinder, through pivoted lever, actuates a switch at proper engine speed so as to connect generator load. Upon pushing off button, load is disconnected. Solenoid valve de-energizes blocking oil flow into hydraulic cylinder and allows cylinder to retract under spring pressure by exhausting cylinder into engine sump through drain circuit of solenoid valve.

Abstract: In a supervisory system (FIG. 7) for the accelerator pedal transducer (26) in an electronic engine control (EMS) for a vehicle engine, the output signal (U-FFG) of the transducer (26) is interpreted to show whether or not the transducer is at or close to the idling position. The resulting information is compared with the states of idling and pressure switches (18, 28) which shows whether or not the accelerator pedal (30) is actually at or close to its idling position. A contradiction resulting from this comparison indicates a fault and remedial action can be taken by the EMS, for example, to reduce the engine power to a precautionary value. A contradiction between other comparisons shows that one of the switches (18, 28) is faulty. In the event of the accelerator pedal sticking in a depressed position after the driver has lifted his foot and depressed the brake (FIG. 5) a brake signal (BS) can be passed through a gating circuit controlled by the idling switch signal (FFG-LL) to produce a reaction signal(RS).

Abstract: A fuel tank vapor control system is provided with an improved device for warning of malfunction of a canister. The device judges on malfunction of the canister on the basis of whether opening of a purge passage is effective for causing an inside temperature fall of the canister. In order to prevent an erroneous judgement on malfunction of the canister on the basis of an overflow condition of the canister, a purge passage is first closed so that the canister fully adsorbs hydrocarbon vapors from a fuel tank and then opened so that an inside temperature fall of the canister occurs. Opening and closing of the purge passage is repeated for several times so that a reliable judgement on malfunction of the canister is formed after lapse of a certain time and under a different operating condition of the canister.

Abstract: A fuel vapor storage canister to prevent breakthrough evaporative emission loss and facilitate purging by concentrating the fuel vapor close to the vent to the engine. The canister is divided into two compartments which communicate through a connective means that only allows vapor into the second compartment when a control valve, located in the connective means, opens at a threshold pressure.

Abstract: A method and an arrangement for the open-loop and/or closed-loop control of the engine power of an internal combustion engine of a motor vehicle is suggested. For checking a safety function, the arrangement intervenes in the fuel metering in the sense of reducing engine speed when an operating condition critical to safety is present. This safety function is triggered in the overrun operation of the internal combustion engine independently of the safety condition and the correct performance is checked. The safety function is detected as being defective when a unlimited metering of fuel takes place in this operating condition when the safety function is triggered.

Abstract: The tank/canister volume's integrity against unacceptable leakage is either confirmed or denied by a diagnostic test performed by an on-board diagnostic system which includes an electrically operated air pump and a pressure switch. At the beginning of a test, the engine management computer closes the canister purge solenoid valve and operates the pump to begin pressurization of the tank/canister volume. Failure to build to a predetermined pressure indicates a gross leak. Upon attainment of the predetermined pressure, the pump is shut off by the operation of the pressure switch from one state to another. The pressure switch has hysteresis so that if the pressure falls below the predetermined pressure by a certain amount during the predetermined duration of the test, the pressure switch returns to its one state thereby giving a signal denying the integrity. Integrity is confirmed by the pressure switch remaining in its another state during the test.

Abstract: The invention relates to a two-handle arrangement for a handheld portable tool having a drive motor and equipped with forward and rearward handles for two-handed operation. Each of these handles includes respective actuating elements which can be actuated only in a specific sequence. First, force must be applied to the actuating element on the forward handle and only when a corresponding actuation of the throttle lever takes place is there an increase in the speed of the drive motor. The invention is especially suited for handheld portable tools equipped with an internal combustion engine such as motor-driven chain saws, hedge trimmers and the like.

Abstract: A malfunction detection apparatus for detecting a malfunction in an evaporated fuel purge system for use in an internal combustion engine. The apparatus includes a vapor passage connecting a fuel tank to a canister for feeding fuel vapor from the fuel tank into the canister, a purge passage connecting the canister to an intake passage of the engine for feeding the fuel vapor adsorbed in an adsorbent in the canister into the intake passage, a purge control valve provided for controlling a flow of the adsorbed fuel vapor in the canister being fed into the intake passage, a pressure sensor provided for outputting a signal indicative of pressure in the vapor passage, and a malfunction detection part responsive to the signal outputted by the pressure sensor for detecting a malfunction in the evaporated fuel purge system.

Abstract: A fuel injection structure for dual fueled combustion engines having access to the combustion chamber of a cylinder to automatically supplement a liquid fuel with a gaseous fuel, the structure being adapted to supply the gaseous fuel by a programmed electronic control circuit which regulates the operation of fuel injection to be in accord with certain sensed engine operation parameters to determine from said parameters a desired gaseous fuel flow rate and a signal responsive to said parameters actuating a valve to control said flow.

Abstract: A method and apparatus for detecting engine overheating and controlling engine ignition timing utilizes a single temperature sensor. The temperature sensor is positioned adjacent a cylinder head of an engine. A rate of engine temperature increase is calculated based on engine temperature information produced by the temperature sensor, and engine speed is regulated based on the calculated rate of engine temperature increase. Ignition timing is also controlled in response to the engine temperature information produced by the temperature sensor, and the engine speed is regulated to a predetermined speed value whenever the engine temperature exceeds a predetermined temperature value.

Abstract: A method and an apparatus for driving an auxiliary device of an internal combustion engine according to the present invention is directed to preventing an over revolution of an engine by detecting a speed of the revolution of the engine, regardless the magnitude of an induced voltage of a primary winding of an ignition device.

Abstract: A self-diagnosing fuel-purging system includes a plurality of temperature sensors for detecting temperatures of an adsorbent in a fuel processing apparatus at different points. The system causes fuel previously adsorbed onto the adsorbent to be purged, and then, determines the state of the fuel adsorbed onto the adsorbent on the basis of the temperatures detected by means of the temperature sensors while fuel-purging is stopped. After the state of the fuel adsorbed onto the adsorbent becomes a predetermined state, the system determines abnormality in itself on the basis of temperature drop of the adsorbent detected by at least one of the temperature sensors while performing fuel-purging.

Abstract: Fluid pressures in an internal combustion engine are monitored by two diaphragm operated valves and open either valve when abnormal pressures are sensed to shut down the engine. Each valve is a sleeve valve slidable on a stem and normally latched to the stem. The stem carries a reset button and is spring biased to hold the valve in closed position. A valve is released from the stem when abnormal pressures are detected and the valve is spring biased to the open position. If the reset button is held in to override the protective function, the latch release and valve opening will still occur.

Abstract: An audible warning arrangement for a supercharged internal combustion engine, such as a turbocharged engine on a boat or truck. A thermostat valve senses the temperature in the air intake manifold of the engine. When this temperature becomes excessively high, the valve opens and passes pressurized air from the manifold into an air horn, which produces an audible warning signal.

Abstract: A failure checking apparatus for use with an internal combustion engine associated with an evaporated fuel purging unit having a canister adapted to accumulate evaporated fuel from a fuel tank. Communication is provided between the canister and the engine to introduce the evaporated fuel from the canister to the engine. The communication is interrupted to permit the canister to accumulate evaporated fuel from the fuel tank when a parameter related to a rate of evaporated fuel produced in the fuel tank exceeds a predetermined value. The communication is introduced into the canister and resumed to permit evaporated fuel to be introduced from the canister to the engine a predetermined period of time after the communication is interrupted. An air/fuel ratio at which the engine is operating is sensed for detecting a first value representing the air/fuel ratio when the communication is held interrupted and a second value representing the air/fuel ratio after the communication is resumed.

Abstract: Methods and apparatus for detecting fuel problems of an internal combustion engine, including low fuel, a plugged fuel filter, a pinched fuel line, air in the fuel system, and gelled fuel. The detection of a fuel system problem is followed by engine shutdown, with shutdown being initiated quickly enough to retain sufficient fuel in the fuel system to re-start the engine without the necessity of priming. The invention includes the detection and counting of predetermined engine speed fluctuations. A timer is started upon the detection of the first predetermined speed fluctuation. If a predetermined count is reached before the timer reaches a predetermined time value, the engine is shutdown when the count is reached. If the timer reaches the time value before the count value is reached, the counter and timer are reset to await another predetermined engine speed fluctuation.

Abstract: An electronic engine protector including an electronic pressure transducer that produces variable voltage output in proportion to the differential pressure of the engine crankcase and the atmosphere. Circuitry is provided for selectively adjusting the pressure trip point which represents the faulted mode wherein the engine's fuel solenoid is turned off. Further, circuitry provides for a selectively adjustable time delay to prevent engine shut down due to momentary engine overloads, atmospheric phenomena, or other such temporary conditions that generate a false shut down signal.

Abstract: A marine propulsion device includes an engine having an alternator for charging a storage battery. A voltage regulator and rectifier is connected in circuit between the alternator and the storage battery and is disposed within a housing in heat exchange relation with cooling liquid disposed in a water jacket of the engine. The regulator and rectifier are driven by the storage battery and a thermostatic switch is disposed in circuit between the battery and the regulator and rectifier for interrupting power thereto when the temperature of the regulator and rectifier exceeds a predetermined limit.

Abstract: The invention relates to a two-handle arrangement for a handheld portable tool having a drive motor and equipped with forward and rearward handles for two-handled operation. Each of these handles includes respective actuating elements which can be actuated only in a specific sequence. First, force must be applied to the actuating element on the forward handle and only when a corresponding actuation of the throttle lever takes place is there an increase in the speed of the drive motor. The invention is especially suited for handheld portable tools equipped with an internal combustion engine such as motor-driven chain saws, hedge trimmers and the like.

Abstract: The invention is directed to a method for protecting a catalyzer against overheating. The method includes the steps of checking whether an injection valve no longer correctly closes by means of a conventional diagnostic process. If the condition is present that an injection valve no longer correctly closes, the air/fuel mixture for all cylinders is enriched and an overrun switchoff is inhibited. The method leads to the condition that in all load ranges, the oxygen quantity reaching the catalyzer is limited so that no damaging afterburning can take place. In this way, the catalyzer is protected against overheating and the affected vehicle is not disabled.

Abstract: An engine protection system and protocol is implemented within an electronic engine control module. Various engine fluid parameters, such as coolant level and temperature, oil pressure and temperature, and air intake manifold temperature, are monitored and compared to limit values to determine if a fluid fault condition exists as to one or more of the fluid parameters. The engine performance is derated as a function of the severity of the fluid parameter fault. Two levels of faults are sensed to activate one of two derating schedules. In one schedule, the engine power, or torque as a function of engine speed, is gradually reduced or derated as the fluid parameter moves farther out of normal operating range. With this derate schedule, the engine will still run and the driver can still operate the vehicle, albeit at lower power levels than a healthy engine.

Abstract: A safety system associated with an engine of a marine vessel wherein the safety system includes a blower, a control unit, and a plurality of sensors. An intake pressure detection device is coupled to the intake manifold of the engine for the detection of pressure at the intake manifold. A sensor is coupled to the engine to monitor oil pressure and, along with the intake pressure detection device, transmits a signal to the control unit, with the signals each having a characteristic corresponding to the respective engine pressure. Detection of an engine pressure associated with engine idling or low cruise operation causes the control unit to activate the blower. The safety system includes interactive heat sensors and vapor sensors to monitor the atmosphere in an engine compartment. Detection of a volatile environment activates the blower and triggers both an audio and a visual warning.

Abstract: A system for preventing overheating of an engine for a vehicle includes a revolution rate detector for detecting the rate of revolution of the engine carried on the vehicle, a device for reducing an engine power output in response to a value detected in the revolution rate detector exceeding a preset revolution rate, a device for predicting overheating of the engine, and a preset revolution rate correcting device for reducing the preset revolution rate in accordance with a reduction of the vehicle velocity in reply to prediction of an engine overheat condition by the overheat predicting device. An overheating due to an engine racing condition during vehicle travelling is prevented in view of an engine cooling effect provided by flowing air.

Abstract: A fuel supplying device for a marine propulsion unit wherein the engine is slowed in response to an abnormal condition by interrupting the ignition. In order to prevent excess fuel consumption and preclude backfiring, the fuel supply is also discontinued when the ignition system is interrupted.

Abstract: A method and an apparatus for protecting an engine from damage due to such factors as piston scuffing and/or knocking. The vibration of the engine is measured and vibrational thresholds indicative of either engine knocking or piston scuffing are generated and the actual engine conditions compared with those criteria. If either knocking or piston scuffing are predicted to occur, protective action is taken by either shutting the engine down, reducing its speed and/or providing additional lubrication for the engine. When protective action is taken, a warning is also given to the operator of a detrimental condition.

Abstract: An engine control apparatus comprises a revolution speed sensor for detecting the number of revolutions of an internal combustion engine, an abnormality detecting means for detecting abnormality in the engine, and a control means for increasing or decreasing the number of misfire cylinders so that the revolution speed of the engine is brought down by a limited degree corresponding to a degree of abnormality of the engine when the abnormality is detected.

Abstract: An automotive engine has a fuel injector provided for injecting fuel directly in a cylinder of the engine. A control unit has a calculator for producing a basic fuel injection pulse width signal. Engine speed at idling state is compared with a desired idle speed and a correcting pulse width is produced. The basic pulse width signal is corrected with the correcting pulse so as to converge the idle speed to the desired idle speed. The correcting pulse width is compared with a reference pulse width and an alarm signal is generated when the correcting pulse width is larger than the reference pulse width. In response to the alarm signal, an alarm is operated to warn the nozzle clog.

Abstract: The shut-down device stops a diesel engine by cutting the fuel supply or the intake air supply. The device comprises a timer having a capacitor which outputs engine stop signals for a predetermined time when a key switch is turned off, and a drive element having a switching device which supplies an actuator for stopping the engine with operation signals in accordance with the engine stop signals from the capacitor. The switching device includes an NPN-type transistor to receive the engine stop signals as a base voltage and to be connected to a starter of the engine, and a PNP-type transistor to receive a divided voltage from a battery in accordance with the starter operation and to output the operation signals to the actuator.

Abstract: An engine control apparatus for an internal combustion engine has a plurality of groups of cylinders. The engine control apparatus has the same number of independent intake manifolds as there are groups of cylinders, isolating the groups of cylinders. Each independent intake manifold has an air flow meter. The engine control apparatus provides electronic fuel injectors of each group of cylinders with an injector control signal having a pulse width determined based on a signal from the air flow meter so as to deliver a correct ratio of air-fuel mixture into the group of cylinders. The engine control apparatus detects whether one of the plurality of air flow meters is at fault. If any one of the air flow meters is at fault, the engine control apparatus adjusts the pulse width of an injector control signal to be provided for the fuel injectors of the group of cylinders having the air flow meter which is at fault, based on a signal provided by another of the air flow meters which is working normally.

Abstract: The invention relates to an electronic engine control (EEC) equipped with a fuel cutoff safety device in the form of a relay 12 for controlling the winding of the fuel pump 16. A single conductor (FCOM) connects the fuel pump power supply line with the EEC in order to test and/or monitor the voltage applied across the terminals of the fuel pump, at least when the engine is started up.

Abstract: An automatic power interrupting system for a vehicular control circuit including a relay switch having a contact connected between a power source and the supply terminal of a control circuit and a relay coil connected with the power source, a control switch connected between the power source and the supply terminal and with the signal input terminal of the control circuit and turned on only by an external force, a revolution detector for detecting engine revolutions and a switching device for turning the relay switch on when power is supplied to the circuit and off after a predetermined time period measured after stop of the engine based on a signal from the revolution detector.

Abstract: A monitoring arrangement for a fuel filter of a diesel internal combustion engine is described. The metering of fuel of the diesel internal combustion engine is open-loop controlled or closed-loop controlled by an electronic control unit. This control unit influences the supply voltage of the sensor and evaluates its output signals for monitoring the function of the fuel filter.

Abstract: In a diesel internal combustion engine comprising an air intake pipe and a throttle valve arranged in the latter, the throttle valve is equipped with a drive in order to prevent operating states which are dangerous for the internal combustion engine, e.g. uncontrolled exceeding of the allowable maximum speed due to disturbances. The drive holds the throttle valve open during trouble-free operation and moves it into a closed position during disturbances. The closed position of the throttle valve is determined in such a way that the remaining reduced air flow cross-section throttles the combustion air passing through to such an extent that the internal combustion engine still runs securely at idling speed and does not exceed a predetermined speed during feeding of a desired quantity of fuel.

Abstract: A safety system against engine overturning contains an inclination sensor for detecting an engine inclination and transmitting a signal representing the engine inclination and a self-hold device operatively connected to the inclination sensor. The self-hold device determines an inclined condition of the engine in response to the signal from the inclination sensor and transmits and holds an engine stopping signal in a case where the detected engine inclination exceeds a preliminarily set allowable inclination. The operation of the engine is stopped in response to the engine stopping signal from the self-hold device. The driving condition of the engine and a fuel pump are determined and controlled by driving condition determining device serving to drive the fuel pump when an engine speed exceeds a preliminarily set reference value while to stop the fuel pump when the engine stopping signal is transmitted from the self-hold device.

Abstract: In a method for the malfunction testing of an idling control arrangement for an internal combustion engine, the closing function of the idling contact is checked. As soon as it is established that the contact should really be closed but that this is not the case, it is certain that there is either an interruption in the idling contact circuit or a servomotor fault. In order to be able to distinguish which of these faults is present, a test movement sequence is carried out in which the servomotor of the arrangement is activated and a check is made whether the throttle flap angle changes. If this is not the case, the servomotor is defective; otherwise, an interruption in the idling contact circuit is present. Using this method, it is for the first time possible to detect interruption and servomotor faults. Until now, it was only possible to detect short-circuit faults.

Abstract: A control system for a variable valve actuating mechanism for an internal combustion engine for varying the lift or timing of intake or exhaust valves in response to engine operating conditions. The control system includes sensors for detecting the pressure in the combustion cylinder and the temperture at the mounting seat of the spark plug. A warning device and fail safe conditions can be activated when an abnormal condition is detected by one of the sensors.

Abstract: Several embodiments of warning systems for marine propulsion engines wherein the operator is provided with a reset device for resetting the warning and wherein the warning is held in its warning mode for a predetermined time even if the operator resets.

Abstract: The invention is directed to a brake light switch circuit arrangement having an additional switch S.sub.2 which opens upon actuation of the brake pedal 13 but only after a first switch S.sub.1 closes. The signals from the two switches are processed by a gating circuit (16, 17, 18) to produce brake signals (B.sub.S1 and B.sub.S2) which are to provide a standby idle-running idle-setting signal (LL*) and switch off a driving-speed controller (FGR) via the main computer (30) of the electronic diesel control. In the event that the brake switch S.sub.1 becomes defective and remains closed while overtaking another vehicle, the condition is prevented that the EDC does not reduce the injected fuel quantity to the idling quantity, even though the accelerator pedal is depressed. It is also prevented that, in the event of a fault in the brake switch (S.sub.1) while the accelerator pedal is released, constant vehicle velocity control by the EDC is not switched off.

Abstract: An apparatus including a housing containing a first and second conductive plate overlapping one another, with the second plate pivotally positionable relative to the first plate to disengage and space the second plate relative to the first plate to disengage electrical communication therebetween, wherein the first plate is in electrical communication with the coil of an automotive engine and wherein the second plate is in electrical communication with the ignition in operative association directing flow of current to the coil. A sealed secondary housing is mounted within the above noted housing and includes a fixed rod mounted to and through a floor of the housing, with the rod in operative communication with a coolant water jacket of an associated internal combustion engine.

Abstract: An engine air intake shutoff apparatus includes a frame that can be attached to and supported by an engine air intake passage such as an engine blower housing over the engine air intake passage. A baffle plate having rollers extending above its surface slidably moves along the side panels of the frame. Rotatable, retractable baffle arms direct the movement of the baffle plate within the housing. The baffle plate has a mitered leading edge that mates with a wedge on the interior of the frame opposite the leading edge of the baffle plate. Baffle arms are secured to rotatable operating shafts at a point above the attachment point of the baffle plate to the baffle arm so that downward force is exerted on the end of the baffle plate. The combination of the mating of the leading edge of the baffle plate and the wedge and the downward and forward force exerted by the baffle arms create an airtight seal between the baffle plate and the frame when the baffle plate is in the closed position.

Abstract: A fail-safe device for an engine temperature sensor. A value of the engine temperature detected by the engine temperature sensor is renewed and stored for engine control. While the engine is detected to be in a low temperature region lower than a predetermined value on the basis of the detected value, renewal of the detected value is inhibited when it has decreased. It is determined that the detected value has decreased, when the detected value is lower than a lower limit value. The lower limit value is set to a value corresponding to the detected value when the engine is detected to be in the low temperature region, whereas it is set to the predetermined value when the engine is detected not to be in the low temperature region. Renewal of the detected value is inhibited when the detected value has not remained within a predetermined range over a predetermined time period.

Abstract: The device comprises a control rod running parallel to the fuel injection pump and affording a rigidly associated collar alongside each pumping element; each such collar is sandwiched between a pair of spring-loaded sleeves slidably mounted to the rod and incorporating a relative pair of peripheral tongues by which the internal metering mechanism of the element is rotated between two limit positions corresponding to the maximum and minimum delivery settings of the pump; the calibrated force of the springs is balanced against the resistance offered by the metering mechanism in such a way as to enable continued operation of the rod even in the event that at least one mechanism should jam at a given point between its two limit positions.

Abstract: An engine fuel flow shut-off system particularly adapted for off-highway dumper trucks includes a shutoff valve interposed in the fuel supply conduit to the truck propulsion engine and which is responsive to a pressure fluid control circuit to close. Compressed gas charge bottles operable from the operator's cab and from a ground position in proximity to the vehicle boarding ladder supply pressure fluid to the valve actuator to provide closure of the valve and closure of a second valve to interrupt engine lube oil pressure to an engine injector system governor. The vehicle on-board fire extinguishing system is also operably connected to the shutoff valve actuator by way of separate pressure fluid sources to effect closure of the fuel shutoff valve upon actuation of the fire extinguishing system from either the operator's cab or the ground position.

Abstract: An engine reverse rotation prevention apparatus provided in an engine having valve opening and closing means which is in slidable contact with a cam provided on a camshaft. The valve opening and closing means is interconnected with a valve. The engine reverse rotation prevention apparatus comprises a release cam of a reverse rotation prevention release lever supported on the camshaft, which is in contact with a cam base of a cam provided on the camshaft. The release cam is provided with a cam lobe that protrudes from the profile of the cam base and rotates in the opposite direction to that of the camshaft when the engine rotates in a reverse direction. Thus, the reverse rotation of the engine is prevented.

Abstract: A fuel injection controlling device for a two-cycle engine includes an electronic fuel injection system having a fuel injection quantity determining device for determining a fuel injection amount in response to a rotational speed of said engine and a throttle opening. A misfire detecting device is provided for detecting a misfire condition of said engine. Further, a device is provided for decreasing the amount of fuel injection upon transition from a misfire condition to a fired condition. The misfire detecting device includes a sensor for detecting an internal pressure of an intake air path, a storage device for storing therein an output value of the sensor and data of an intake air path internal pressure in a predetermined operating condition of the engine upon normal combustion, and a comparison device for comparing the output value with data read out from the storage means to detect a difference in pressure.

Abstract: A plurality of reference pressures for pressure in an intake passage of the engine is stored in a memory so as to be derived in accordance with speed of the engine and opening degree of a throttle valve of the engine. A reference pressure is derived from the memory in accordance with the engine speed and the corrected opening degree. The pressure in an intake pipe is compared with the reference pressure. A fail-safe signal is generated when the intake pipe pressure is higher than the reference pressure. In response to the fail-safe signal, the fuel supply for the engine is cut off when the engine speed is higher than a predetermined speed.

Abstract: An ignition device for an engine comprises a signal generator to generate a signal in synchronism with the rotation of an engine, a waveform shaping circuit to shape the waveform of an output signal produced from the signal generator, an ignition device to determine ignition timing on the basis of the output of the waveform shaping circuit and to cause ignition in the engine, an ignition-cut controlling circuit to cut the igniting operation of the ignition device when the engine operates at more than a predetermined revolution number, a tachometer signal output circuit to detect the revolution number of the engine on the basis of the output of the waveform shaping circuit, and a tachometer driving means to receive the output of the tachometer signal output circuit and to drive a tachometer so as to indicate an engine speed.

Abstract: A fuel injection pump including a pump piston, which pumps fuel at injection pressure to an injection nozzle as long as a control valve blocks the flow of the fuel, which overflows from the pump work chamber via a flow conduit, to a low-pressure chamber. In this operating state, if the control valve jams and the supply of fuel to the pump work chamber is not completely prevented. A Venturi pump is provided to evacuate the fuel. By means of the Venturi pump with a permanent flow of fuel through it, the static pressure is partially dropped at a flow throttle and this negative pressure is utilized at bottom dead center (UT) of the pump piston to evacuate the pump work chamber by suction, thereby preventing an unintended injection. The apparatus is especially suitable for high-pressure injection in Diesel engines, to achieve redundantly safe operation.