Abstract: The engine protection device affects the engine operation when a low oil level is sensed by releasing substantially all of the compression pressure in the combustion chamber to prevent engine starting, to stop a running engine, or to reduce engine speed. The engine protection device includes a paddle or float whose movement is responsive to the crankcase oil level, an arm connected to the paddle or float, and a pivotable, yoke-type mechanical compression release mechanism that pivots in response to the movement of the arm. The compression release yoke has a first cam member that engages a valve tappet surface. When a low oil level is sensed, the paddle or float pivots the arm and the first compression release member, causing the first cam member to engage the tappet surface to substantially open the intake or exhaust valve. The invention may include a second, easy start compression release member that partially releases the compression pressure to promote engine starting.

Abstract: An air-fuel ratio control apparatus for an internal combustion engine for learning and controlling an air-fuel ratio accurately even during execution of purging of evaporated fuel. The evaporated fuel generated in a fuel tank is adsorbed to a canister, and the adsorbed fuel is evaporated and purged together with air to the intake side of the internal combustion engine through a purge valve. During normal purge rate control by the purge valve, air-fuel ratio feedback values detected by an oxygen sensor are averaged, and the concentration of the evaporated fuel taken into the internal combustion engine through the purge valve is detected by the deviation from a stoichiometric air-fuel ratio 1 of the averaged value and the purge rate. Further, after the lapse of a predetermined period of time after purging is started, air-fuel ratio learning values are renewed in accordance with the air-fuel ratio feedback value and stored in a RAM.

Abstract: An evaporative fuel processing system adapted to be capable of detecting abnormality of an evaporative emission control system for storing, in a canister, evaporative fuel generated from a fuel tank for holding fuel to be supplied to an internal combustion engine, and purging evaporative fuel into the intake system of the engine. A first control valve is arranged across a passage extending between the fuel tank and the canister. A second control valve is arranged across a passage extending between the canister and the intake system of the engine. A third control valve is provided for an air inlet port of the canister communicatable with the atmosphere. Through operating these control valves to open and close them, the evaporative emission control system is negatively pressurized, and abnormality of this system is detected based on the pressure detected in this negatively pressurized state thereof. Timing for carrying out abnormality determination is determined depending on conditions of the fuel tank.

Abstract: An evaporative fuel-purging control system for an internal combustion engine includes at least one flowmeter arranged across a purging passage for outputting a detection parameter indicative of a flow rate of a gaseous mixtured purged through the purging passage, and a purge control valve arranged across the purging passage for controlling the flow rate of the gaseous mixture based on a control parameter indicative of a control amount for the purge control valve. One of the detection parameter and the control parameter is corrected based on a value of the one of the detection parameter and the control parameter assumed when the other of the detection parameter and the control parameter assumes a value corresponding to a state in which the flow rate of the gaseous mixture is equal to the minimum value.

Abstract: In an evaporation fuel control system, a failure diagnosis monitor of the evaporation fuel control system in the limited stable operating state, such as an exhaust gas mode or the like, can be performed so that the failure state is early detected and discharge of hydrocarbon (HC) into the atmosphere due to a leakage of the evaporation fuel from the evaporation fuel control system is prevented.

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 tank-mounted analog pressure transducer. 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. The pumped air is introduced via the canister's atmospheric vent port so that the pressurizing air is entrained with fuel vapors previously collected in, but not yet purged from, the canister. Failure to build to a predetermined pressure within a predetermined time indicates a gross leak. Upon attainment of the predetermined pressure, the pump is shut off. If the pressure drops by more than a certain amount during the test, integrity is denied. If not, integrity is confirmed.

Abstract: A malfunction detecting apparatus for an evaporated fuel purge system includes a first control valve for controlling a flow of fuel vapor in a purge passage between a canister and an intake passage, a second control valve for controlling a flow of air from the atmosphere to the canister via an air inlet opening of the canister, a first control part for turning OFF the second control valve and for turning ON the first control valve during a first time period, so as to subject the purge passage, the canister, and a vapor passage to a negative pressure of the intake passage during the first time period, and a first discriminator for detecting whether or not a malfunction has occurred in the system, in accordance with a pressure change rate derived from pressures of the system sensed at a start of the first time period and at an end thereof.

Abstract: An internal combustion engine has an evaporated fuel purge system for directly feeding evaporated fuel of a fuel tank into an intake pipe of the engine during the engine is running. This system comprises a purge control valve for opening or closing a flow line which connects an upper space of the fuel tank with the intake pipe, a controller for controlling the operation of the valve, a throttle section formed in series with the purge control valve, and pressure and temperature sensors which are located on the upstream side of the throttle section for detecting a pressure and a temperature of the evaporated fuel. When a value detected by the pressure sensor exceeds a predetermined value of pressure for providing a critical pressure ratio at which a flow rate of the evaporated fuel at the throttle section substantially equals to a sonic velocity, the controller opens the purge control valve to cause a purged flow of the evaporated fuel whose flow rate is constant.

Abstract: A fuel-flow alarm includes a fuel-flow detector for detecting the volume of fuel flowing in a conduit connecting a fuel tank to an engine fuel supply device and provides a warning when the volume of fuel is either above or below predetermined limits. The fuel-flow alarm includes a setting unit used to pre-set fuel-flow limit values for various operational states of the engine, detectors which detect the operational status of the engine, a compensation unit for adjusting the pre-set fuel flow limit values in dependence upon the operational status of the engine and a comparator which compares the limit values outputted from the compensation unit with the actual, detected flow rate. When a determination is made that the fuel flow rate exceeds at least one permissible limit value, the alarm is activated.

Abstract: A fuel outflow preventing apparatus of a fuel tank for a vehicle has an object to prevent fuel outflow from the fuel tank when the vehicle is inclined or turned over. Therefore, this apparatus comprises a canister, a float valve provided in an air chamber of the fuel tank, which float valve is closed when the level of fuel in the fuel tank is equal to or higher than a predetermined level and when the vehicle is inclined or turned over, a fuel outflow preventing valve provided in an upper portion of the air chamber of the fuel tank, which fuel outflow preventing valve is closed when the vehicle is inclined or turned over, a first evaporation passage for communicating the float valve with the canister, a second evaporation passage for communicating the fuel outflow preventing valve with the canister, and opened/closed valve device provided in the second evaporation passage.

Abstract: The evaporative emission control system of an internal combustion engine is tested by closing the purge air inlet from the atmosphere, applying a vacuum signal to the system, storing the value of a closed loop air/fuel adjustment at the time the vacuum signal is first applied, sensing for the vacuum signal at a specified point in the system and indicating a fault condition if the vacuum signal is not sensed within a first time period and when the amount of the closed loop air/fuel adjustment at the end of a second time period varies from the stored adjustment by an amount less than a predetermined amount.

Abstract: A failure-detecting device detects failure of a tank internal pressure sensor for an internal combustion engine. The tank internal pressure sensor is provided in a fuel tank for detecting pressure within the fuel tank. The failure of the tank internal pressure sensor is detected by detecting an amount of variation in an output from the tank internal pressure sensor occurring within a predetermined time period elapses after the start of the engine and determining that the tank internal pressure sensor is abnormal when the amount of variation is below a predetermined value upon the lapse of the predetermined time period. A fail-safe device inhibits abnormality diagnosis of the evaporative emission control system when it is determined that the tank internal pressure sensor is abnormal.

Abstract: A tank internal pressure-detecting device for an internal combustion engine having an evaporative emission control system for controlling purging of evaporative fuel generated in a fuel tank thereof into an intake system thereof. An ECU interrupts purging of evaporative fuel by the evaporative emission control system for a predetermined period of time after the engine is started. The ECU causes control valves of the evaporative emission control system to open the interior of the fuel tank to the atmosphere, and stores a value of pressure within the fuel tank detected by a tank internal pressure sensor as a reference value while the purging is being interrupted and at the same time the interior of the fuel tank is opened to the atmosphere. The ECU corrects an output value of the tank internal pressure sensor, based upon the reference value stored.

Abstract: Method and apparatus for automatically starting an EMD locomotive engine.

Abstract: A method for checking the operability of a tank-venting system for a motor vehicle having an internal combustion engine with a lambda controller, which system has an adsorption filter with a connecting line to a tank and a connecting line to the intake pipe of the engine which is provided with a tank-venting valve. The method is characterized in that a lean correction check is performed as soon as an operating condition with low air throughput through the engine is present. If the check determines a lean correction (.DELTA.FR) of the lambda controller which is less than a pregiven lean correction threshold value (.DELTA.FR.sub.-- SW), there is a pressure change check provided with respect to the pressure in the tank as soon as an operating condition is present with a high air throughput through the tank-venting valve. The tank-venting system is deemed to be operative if a pressure change effect of pregiven quality (.DELTA.Dp>.DELTA.Dp.sub.-- SW) is determined.

Abstract: An evaporative fuel-purging control system for an internal combustion engine incorporates a flowmeter arranged across a purging passage for outputting an output value indicative of the flow rate of a mixture of evaporative fuel and air being purged through the purging passage. Abnormality of the flowmeter is determined, based on a value of the output value therefrom assumed when the purging of the gaseous mixture is stopped. Alternatively or in combination, abnormality of the flowmeter is determined, based on a value of the output value therefrom assumed when the purging of the gaseous mixture is resumed after stoppage thereof.

Abstract: A system for protecting an engine equipped with an electronically controlled fuel injection apparatus, in which a battery voltage is detected. When the detected battery voltage is smaller than a predetermined reference value, performance of the engine is degraded, and when the detected battery voltage is smaller than a reference value, that is smaller than the predetermined value, the engine is stopped.

Abstract: This invention relates to a diagnostic system that detects a leak in an engine vapor handling system by checking whether a predetermined pressure or vacuum is attained in a fuel tank when a corresponding temperature change occurs in the fuel tank while the engine was not running.

Abstract: This invention tests the mechanical integrity of an evaporative purge system and fuel system by applying a vacuum to a fuel tank and measuring the extent to which this vacuum bleeds down over a time period. Included in the test method are the steps of closing the vapor management valve positioned between the engine manifold and the evaporative purge flow path of the fuel tank; waiting a predetermined period of time; and obtaining an indication of the extent to which pressure is increasing in the fuel tank due to vapor generation.

Abstract: A hydraulic-controlled electronic governor employed in a fuel injection system is provided with a proportional pressure-reducing solenoid valve (10) capable of conducting a self-regulation of an input hydraulic pressure supplied from a hydraulic pressure source (30). Such pressure-reducing solenoid valve (10) is connected with a control rack (25) for controlling an amount of fuel injection, while interposed between the hydraulic pressure source (30) and a pressure input chamber (28) of a power piston/cylinder mechanism (22) for controlling the control rack (25), so that the input hydraulic force acting on one side of the piston (24) of the power piston/cylinder mechanism (22) balances the resilient force of a return spring (27) acting on the other side of such piston (24) so as to control the control rack (25) in its position.

Abstract: An engine throttle control system comprises a control unit for controlling the position of a throttle by means of a motor in response to a position transducer actuated by an accelerator pedal. A detector detects when a signal produced by the control system is outside a range of acceptable values and, for instance, shuts down the engine. In one embodiment, the detector detects whether power supplied to the motor is less than a value expected on the basis of the position and speed of movement derived from the output of a throttle position sensor.

Abstract: A device for detecting a malfunction of the evaporative control system comprises a two-way flow device in the atmospheric air vent of the evaporative canister with a sensor to detect whether fluid is flowing through the canister during selected operating conditions.

Abstract: An abnormality detection system is provided, which detects abnormality in an evaporative fuel control system for an internal combustion engine. A plurality of temperature sensors are arranged in an evaporative fuel storage device at different locations for detecting the temperature of an adsorbent or in the vicinity thereof within the storage device at the different locations. An ECU controls at least one of charging of evaporative fuel from the fuel tank to the storage device and purging of evaporative fuel from the storage device to the intake system of the engine. The ECU determines the presence or absence of an abnormality in the evaporative fuel control system, based upon output values from the temperature sensors assumed when the control system is operative. A state in which adsorption of evaporative fuel generated in the fuel tank to the adsorbent of the storage device has been completed is detected, based upon the amount of a rise in temperature detected while the charging is being effected.

Abstract: A control system for automatically controlling the operation of a hydraulic system for heavy construction equipment. The system of this invention provides a controller optimally connected to sensors and to control devices on the hydraulic system so that it automatically and optimally preheats the engine coolant and the hydraulic fluid of the heavy construction equipment before a normal starting operation in order to reach to an optimal operating temperature in a relatively short time. The control system automatically checks the operating temperature of the engine coolant and the hydraulic fluid by temperature sensors, and alarms the operator to any overheat condition by an alarm device. The control system also automatically controls the operational mode in order to remove the overheat condition thus preventing the temperature of the engine coolant and the hydraulic fluid from rising above a predetermined temperature.

Abstract: An arrangement for a main fuel pump, a backup fuel pump, a main hydraulic pump, and a backup hydraulic pump, typically for a as turbine engine in an aircraft, includes an isolated fuel and hydraulic fluid system and a backup pumping arrangement employing two mechanically-coupled gear-type reversible pump-motors and appropriate control valves.

Abstract: In an electrically controlled actuation of a load adjusting element (3) corresponding to the position of an arbitrarily adjustable transmitter member (28) and corresponding to other parameters with the aid of a control device (19) and an electrically controlled adjusting device (16) the problem arises that it is necessary that actuation of the adjusting lever (3) of the fuel injection pump still be possible during failure of the electrical control unit or power supply. This is effected in that the transmitter member (28) and the adjusting device (16) are coupled in each instance via a coupling (23, 32) which can be locked by hydraulic and/or pneumatic adjusting means, one of which is locked and the other unlocked depending on the operating situation.

Abstract: A failure detection device that detects a failure occurring in an evaporative fuel purge system by detecting the pressure inside a vapor passage and a purge passage. The vapor passage and the purge passage are connected via a bypass passage. A pressure sensor is connected to either the vapor passage or the purge passage. An engine control unit is provided which judges that a failure has occurred in the evaporative fuel purge system when the pressure sensor detects a pressure equal to or higher than the predetermined pressure.

Abstract: In a fuel control system which has both high pressure fuel system and ordinary fuel control system operated in accordance with the operating conditions of the engine, highly pressurized fuel is regulated by a high pressure regulator in a high pressure fuel injection system for operating a direct fuel injection engine, and an abnormality deciding control system judges abnormality of the high pressure pump. The abnormality is indicated if the abnormality occurs. Thus, the driver can know the abnormality at an early stage and avoid various troubles.

Abstract: A malfunction detection apparatus for detecting a malfunction in an evaporated fuel purge system in which fuel vapor from a fuel tank is adsorbed in an adsorbent in a canister and the adsorbed fuel vapor in the adsorbent is purged into an intake passage of an engine. The apparatus includes a detection part for detecting a concentration of fuel in the fuel vapor purged into the intake passage so that a change in the detected fuel concentration from a time when a purge cutting is performed to a time when a purging is performed after the purge cutting has been performed is detected, and a discrimination part for determining whether there is a malfunction in the system on the basis of the change in the detected fuel concentration by the detection part.

Abstract: The present invention relates to a method and apparatus for preventing an impaired person from operating a vehicle. The method includes a means for evaluating the level of the necessary skills for the safe operation of motorized vehicles, including automobiles, watercraft, aircraft and machinery. Once this level is determined on an individual basis, before operation of the motorized vehicle can be effected, each individual must match or surpass the safety level for enabling the ignition of the device. If the individual is impaired such as by drugs or alcohol use, the evidence is retained and the ignition disabled to prevent operation of the motorized vehicle. The apparatus includes an electronic module necessary to activate a test routine or program which also records the time, identity of the user, the number of times passed or failed and any attempts to tamper with our circumvent the system.

Abstract: A safety device for a single cylinder internal combustion engine powered implement includes a solid state ignition circuit for producing a spark in a spark plug. The ignition circuit includes a first coil for generating a normally timed sparking voltage in the circuit for normal engine operation, and a second coil for generating an advanced timed sparking voltage in the circuit for stopping the engine. The first and second coils are each disposed about the periphery of the flywheel and angularly displaced from each other. A deadman control having a first and second position, selectively decouples one of the coils from the ignition circuit depending on the state of position of the deadman control.

Abstract: A method of detecting conditions during the operation of a transport refrigeration unit (20) which may cause shutdown, and then modifying the operation of the unit in an attempt to find an operating condition that will keep the unit operating safely. The unit includes a compressor (26) driven by an engine (30) operable at low and high speeds. Upon detecting (264) an over-temperature condition of the engine a first modification (282) is initiated, including switching the engine to low speed. If the engine temperature does not drop to a safe value (288, 292), a second modification (296) is initiated. If the engine was in low speed (280) when the over-temperature condition was detected, the second modification is initiated immediately. Upon detecting (314) a low oil pressure condition, the engine is switched (316) to high speed. If the oil pressure rises to a safe level, engine operation is continued at high speed. Appropriate alarms (326) accompany the modified operating conditions.

Abstract: A line (3) provided between the head space (11) of the fuel tank (10) and the induction tube (1) of the engine contains an absorption element (9) and can be shut off by a signal-actuated servo valve (8) connected to the outlet from the absorption element. The line (3) is provided with a first sensor (4) preceding the absorption element (9) and detecting gas flows. A vacuum actuator (12) following the servo valve (8) is provided with a second sensor (13) which gives a signal when actuated. The first sensor (4) and the second sensor (13) are connected for carrying signals to a diagnosis block (14) which compares them with the signal (17) actuating the servo valve (8) and uses them for fault diagnosis.

Abstract: A tank-venting arrangement includes: a tank; an adsorption filter connected to the tank; a tank-venting valve interconnecting the adsorption filter and the intake pipe of the engine; a control unit for driving the tank-venting valve so that it closes or opens; a pressure difference sensor for measuring the pressure difference between the pressure in the tank and the ambient pressure; and, an integrating unit for determining the time integral of the pressure difference. With this tank-venting arrangement, a simple and reliable determination can be made as to when so much fuel vapor should have been adsorbed in the active charcoal filter so that when the tank-venting valve is opened thereafter, a lean correction by means of a lambda controller can be required. If this lean correction is not made, this is an indication that the fuel flowing from the tank has not reached the tank-venting valve so that the tank-venting arrangement leaks or is obstructed.

Abstract: An engine air shutdown valve comprising a gate which is movable from a first position wherein the air flow passage of an engine is relatively unimpeded to a second position where the air flow passage is closed thereby terminating operation of the engine. A trip spindle maintains the gate in its open position with a ball release. Upon activation of the ball release, the gate moves parallel to the direction of air flow through the passage to terminate the air flow.

Abstract: This invention teaches a system for interrupting operation of the internal combustion engine of a vehicle so as to prevent an undesirably high level of carbon monoxide in the ambient by using the voltage output signal from an engine oxygen sensor placed in the exhaust stream. Engine operation is interrupted when there are simultaneous signals indicating both an EGO sensor signal level above a predetermined value and idling condition of the engine.

Abstract: A flame arrester comprises a continuous flame arresting member in the form of a helix having offset interstices between adjacent turns of the helix. The flame arrester further comprises a mechanism for housing the flame arresting member. Upon installation of the flame arrester on a carburetor, air intake system, or any source of flammable gases, any backfire or flame passing through the flame arrester will be extinguished.

Abstract: In an evaporative emission-control system having a canister for trapping a fuel-vapor evaporated from the fuel tank and a purge control valve for executing a purging, an amount of fuel-vapor trapped in the canister is measured while the engine is stopped or in an idle state. The trapped fuel-vapor is purged from the canister and mixed with an air-fuel mixture when the amount of fuel-vapor trapped in the canister is sufficient for diagnosis while the vehicle is running in a predetermined driving condition. In this purge operation, a concentration of a vapor-laden air from the canister is measured and the occurrence of an abnormal state of the evaporative emission-control system is determined when a change of the concentration of the vapor-laden air after the purging is less than a predetermined value.

Abstract: A common-rail fuel injection system for an engine includes a common rail for storing fuel. A plurality of pumps supply fuel to the common rail. Fuel is injected into the engine from the common rail. Feedback control is executed on the pressure of the fuel in the common rail. A device serves to detect whether or not at least one of the pumps fails. An arrangement decreases the pressure of the fuel in the common rail when the detecting device detects that at least one of the pumps fails.

Abstract: A method of detecting conditions during the operation of a transport refrigeration unit which may cause shutdown, and then modifying the operation of the unit in an attempt to find an operating condition that will keep the unit operating safely. The unit includes a compressor driven by an engine operable at low and high speeds. Upon detecting an over-temperature condition of the engine a first modification is initiated, including switching the engine to low speed. If the engine temperature does not drop to a safe value, a second modification is initiated. If the engine was in low speed when the over-temperature condition was detected, the second modification is initiated immediately. Upon detecting a low oil pressure condition, the engine is switched to high speed. If the oil pressure rises to a safe level, engine operation is continued at high speed. Appropriate alarms accompany the modified operating conditions.

Abstract: This invention teaches a system for interrupting operation of the internal combustion engine of a vehicle so as to prevent an undesirably high level of carbon monoxide in the ambient. Engine operation is interrupted when there are simultaneous signals indicating a carbon monoxide level above a predetermined value and and idling condition of the engine.

Abstract: This invention teaches a system for interrupting operation of the internal combustion engine of a vehicle so as to prevent an undesirably high level of carbon monoxide which would cause a low level of oxygen in the ambient. Engine operation is interrupted when there are simultaneous signals indicating an oxygen level below a predetermined value and an idling condition of the engine.

Abstract: A tank-venting arrangement includes: a tank having a tank closure; an electrically drivable check valve; an adsorption filter; connecting lines for interconnecting the above components; a difference pressure sensor which measures the pressure difference between the pressure in the tank and the ambient pressure and supplies a pressure difference signal; a comparator which, at least for a running engine, compares the pressure difference signal to upper and lower threshold values and supplies an opening signal to the check valve to open the latter when the pressure difference signal is greater than the upper threshold value and a closure signal for closing the check valve when the pressure difference signal drops below the lower threshold value; and, a detector unit which supplies an opening signal to the check valve for opening the check valve when the sensor determines a possible opening of the tank and a closure signal for closing the check valve when the sensor determines a possible closure of the tank.

Abstract: A tank-venting system has an adsorption filter (AF) with a venting line (BL) which can be shut off by means of a controllable shut-off valve (AV). The shut-off venting valve makes it possible to set underpressures and overpressures in the system in a concerted manner in order to check its operability. As a result, particularly reliable information relating to the operability can be obtained.

Abstract: An engine throttle control system comprises a control unit for controlling the position of a throttle by means of a motor in response to a position transducer actuated by an accelerator pedal. A detector detects when a signal produced by the control system is outside a range of acceptable values and, for instance, shuts down the engine. In one embodiment, the detector detects whether stress in an accelerator pedal return spring is less than a value expected.

Abstract: An on-board diagnostic system determines if there is a leak in the portion of a canister purge system that includes the fuel tank and the canister that collects volatile fuel vapors from the fuel tank's headspace. A vacuum regulator/sensor placed in the conduit between the CPS valve and the canister, includes a switch providing a signal indicating the presence or absence of a leak. The sensor also indicates both positive and negative pressures relative to a reference pressure such as atmosphere. During diagnostic testing, the switch is closed and if the switch becomes open this indicates a leak in the headspace of fuel tank on the canister.

Abstract: A tank-venting arrangement for a motor vehicle includes a fuel tank KT having a HC (hydrocarbon)-sensor, an adsorption filter AF and a tank-venting valve TEV. If the HC-sensor annouces that fuel vapor above a pregiven concentration is present in the tank, then it is expected that a lambda correction in the lean direction is required when the tank-venting valve is opened. If such a correction is not determined, this shows that either the arrangement leaks or the tank-venting valve does not open correctly. For carrying out the mentioned testing method, this arrangement requires only a single additional sensor, namely, the HC-sensor mounted in the tank. The arrangement is therefore simpler than known arrangements and nonetheless permits carrying out a reliable method for checking the operability.

Abstract: An air filter device is disclosed which includes a dry air filter and a dust precipitator for an internal-combustion engine, having a dust extraction blower in a dust exhaust-air line leading away from the dust precipitator. In order to maintain perfect operation of the internal-combustion engine, in addition to the dust exhaust-air line there is provided an additional exhaust-air line which is connected to the intake side of the motor-driven blower and has a shut-off element which opens in the event of failure of the dust extraction blower.

Abstract: An evaporative fuel-purging control system for an internal combustion engine comprises a mass flowmeter and a differential pressure type flowmeter arranged in a purging passage of the engine for measuring a flow rate of a mixture of evaporative fuel and air being purged. The flowmeters have different output characteristics relative to change in the concentration of evaporative fuel in the mixture from each other. Output values from the flowmeters are compared to obtain a difference or a ratio therebetween. Failure of at least one of the flowmeters is detected based upon the difference or the ratio.

Abstract: An evaporative fuel apparatus includes a first purge passage which connects a canister and an intake passage of an internal combustion engine and through which fuel vapor, stored in the canister, is purged into the intake passage, a control part provided in the first purge passage for controlling a flow of fuel vapor being fed from the canister to the intake passage, a detecting part for detecting a malfunction occurring in the control valve, a second purge passage which connects the canister and the intake passage and through which fuel vapor, stored in the canister, is purged into the intake passage, and a passage switching part for carrying out a passage switching to the second purge passage if a malfunction is detected by the detecting part, allowing the fuel vapor from the canister to be fed into the intake passage through the second purge passage.