摘要:
A deviation DGAIR between a first induction air volume GAIRTH that is calculated (S10) based on a detected value (Gair) of an air flow meter and a second induction air volume GAIRPB that is calculated (S12) based on an absolute pressure (PBA) is calculated (S14), and a mean value DGAIRAVE of the deviation DGAIR is calculated (S16, S18), whereby when a difference DDGAIR between the deviation DGAIR and the mean value DGAIRAVE is larger than a predetermined value DGAIL1 (or when a correction mode AFMMODE is 1), secondary air is determined to be supplied to an engine, and the first induction air volume GAIRTH is then corrected (S24, S26).
摘要:
A fault determining apparatus for a variable valve timing mechanism is provided for shortly and accurately determining a fault even at low oil temperatures. The mechanism is driven by an oil pressure to change a cam phase of an intake cam and/or an exhaust cam with respect to a crank shaft of an internal combustion engine, thereby controlling the actual cam phase to reach a target cam phase. The apparatus has a fault determining routine executed by an ECU (electric control unit) for determining that the mechanism is faulty when a cam phase difference between the target cam phase and the actual cam phase is not within a predetermined range, an oil temperature sensor for detecting the temperature of the working oil, and a correcting routine executed by the ECU for correcting the predetermined range in an increasing direction when the detected oil temperature is low.
摘要:
A failure diagnosis apparatus for diagnosing a failure of an evaporative fuel processing system. The system includes a fuel tank, a canister having adsorbent for adsorbing evaporative fuel generated in the fuel tank, an air passage connected to the canister for communicating the canister with the atmosphere, a first passage for connecting the canister and the fuel tank, a second passage for connecting the canister and an intake system of an internal combustion engine, and a purge control valve provided in the second passage. A pressure in the evaporative fuel processing system is detected. An opening of the purge control valve is controlled by changing a duty ratio of a drive signal which drives the purge control valve. First and second filterings of the detected pressure are performed. A second passing frequency band of the second filtering is narrower than a first passing frequency band of the first filtering. A flow rate abnormality of a purge gas flowing in the second passage is determined based on the filtered pressures.
摘要:
A failure diagnosis apparatus for diagnosing a failure of an evaporative fuel processing system. A pressure in the evaporative fuel processing system is detected, and a purge control valve and a vent shut valve are closed when stoppage of the engine is detected. A determination is made as to whether there is a leak in the evaporative fuel processing system based on the detected pressure during a predetermined determination period after closing of the purge control and vent shut valves.
摘要:
An atmosphere-vented valve (a pressure relief section) is opened in a predetermined amount so as to reduce an inside pressure of a canister to a predetermined negative pressure (S14) while preventing an inside pressure in a fuel tank from becoming an excessively negative pressure by closing a charge passageway opening and closing valve (S18), and purging is controlled while the canister inside pressure is being reduced, whereby from a similar principle to that of vacuum distillation, the release of vaporized fuel from an absorbent is promoted so as not only to increase the purge efficiency but also to prevent the application of an unnecessary stress to the fuel tank.
摘要:
There is provided a valve timing control system for an internal combustion engine, which is capable of properly controlling valve timing while maintaining the accuracy of degradation determination of an oxygen concentration sensor or an exhaust gas-purifying device. The valve timing control system for an internal combustion engine includes a degradation-determining system that performs degradation determination of at least one of the oxygen concentration sensor and the exhaust gas-purifying device in a state in which the air-fuel ratio of a mixture supplied to the engine is controlled to a predetermined state, and controls valve timing by changing the cam phase. An ECU determines whether or not executing conditions for the degradation determination by the degradation-determining system are satisfied. When it is determined that the executing conditions for the degradation determination are satisfied, a change in setting of the target cam phase, which is to be executed in dependence on operating conditions of the engine, is restricted.
摘要:
A failure diagnosis apparatus for diagnosing a failure of an evaporative fuel processing system wherein a pressure in the evaporative fuel processing system is detected, and a purge control valve and a vent shut valve are closed when stoppage of the engine is detected. A determination is made as to whether there is a leak in the evaporative fuel processing system based on the detected pressure during a predetermined determination period after closing of the purge control and vent shut valves. The determination result is decided according to a parameter indicative of an amount of evaporative fuel generated in the fuel tank after stoppage of the engine.
摘要:
An atmosphere-vented valve (a pressure relief section) is opened in a predetermined amount so as to reduce an inside pressure of a canister to a predetermined negative pressure (S14) while preventing an inside pressure in a fuel tank from becoming an excessively negative pressure by closing a charge passageway opening and closing valve (S18), and purging is controlled while the canister inside pressure is being reduced, whereby from a similar principle to that of vacuum distillation, the release of vaporized fuel from an absorbent is promoted so as not only to increase the purge efficiency but also to prevent the application of an unnecessary stress to the fuel tank.
摘要:
An evaporative fuel processing system for processing evaporative fuel generated a fuel tank. A canister temporarily stores evaporative fuel generated in the fuel tank. A charge passage connects the fuel tank and the canister. A first purge passage connects the canister and an intake pipe of an internal combustion engine having a turbocharger. A purge control valve is provided in the first purge passage for adjusting a flow rate of gases flowing through the first purge passage. A second purge passage connects a downstream side of the purge control valve of the first purge passage and an upstream side of the turbocharger of the intake pipe. A jet pump is mounted on the second purge passage. A pressurized air supply passage supplies air pressurized by the turbocharger to the jet pump. The jet pump includes a nozzle for discharging the pressurized air supplied through the pressurized air supply passage.
摘要:
There is provided a failure determination apparatus which is capable of determining the failure of a temperature sensor promptly and correctly regardless of environmental conditions at the start of an internal combustion engine. An ECU calculates an operation progress parameter indicative of a degree of progress of operation of the internal combustion engine from the start thereof. A RAM of the ECU stores a value of the temperature detected by the temperature sensor at a stoppage of the engine. Further, the ECU measures a stop time period from the stoppage to a start of the engine, and determines that the temperature sensor is faulty, when the difference between a value of the temperature detected by the temperature sensor at the start of the present operation of the engine and the value of the temperature stored in the RAM is equal to or smaller than a predetermined reference value on condition that the operation progress parameter calculated during the immediately preceding operation of the engine is larger than a predetermined value, and that the stop time period before the present operation of the engine is longer than a predetermined time period.