摘要:
Detection of abnormalities of an idle speed control system is performed based on whether a deviation of an on-idle engine speed from a target engine speed is within a critical range which is changed so as to make the idle speed control system harder to be judged abnormal when the engine is in a lapped state where the engine is apt to change speed than when in a green state where the engine is hardly changeable in speed.
摘要:
A valve operation verifying system for making verification of valve operation of an EGR valve of a type having a diaphragm elastically deformable according to operating conditions of an engine to admit controlled amounts of exhaust gas that is recirculated into an intake air stream which verifies, on a basis of gas pressure in an EGR passage, whether the diaphragm remains elastically deformable as specified and whether a pressure sensor remains free from freezing, and executes the verification of valve operation of the EGR valve on a basis of a change in the gas pressure in the EGR passage when the EGR valve opens and when it closes, and when the temperature of ambient air is lower than a critical point, verifying that the diaphragm remains elastically deformable as specified and that said pressure sensor is free from freezing.
摘要:
A leakage diagnostic system for making a judgement of leakage of a fuel purge system, which has in order from the side of a fuel tank a control valve, a canister and a purge valve disposed in a purge passage and a relief valve isolating the canister from the atmosphere, based on a rising rate of pressure in the purge passage between the fuel tank and the intake system isolated from the atmosphere after lowering and keeping the interior of the purge passage below specified negative pressure level for a specified period of time. When the interior of the fuel tank increases above a threshold level after a specified period of time, the leakage diagnostic system delivers a judgement of leakage of the purge system.
摘要:
A method for detecting an abnormality in a hybrid vehicle. The hybrid vehicle includes an engine that can run in a cylinder cut-off state where intake and exhaust valve lifts are made zero, and a motor/generator that functions as both a motor and a generator. The vehicle travels by means of the power of at least one of the engine and the motor/generator and carries out regenerative braking by the motor/generator while running the engine in a cylinder cut-off state during deceleration. When detecting an abnormality in a negative intake pressure sensor or an EGR control valve based on the negative intake pressure of the engine, the engine is prohibited from running in a cylinder cut-off state even during deceleration, thus generating a negative intake pressure and thereby enabling the abnormality detection to be carried out without any problems.
摘要:
An exhaust gas purifying apparatus for an internal-combustion engine, including a three-way catalyst, nitrogen oxide purifier that is disposed downstream of the three-way catalyst, an upstream oxygen sensor that is disposed between the three-way catalyst and the nitrogen oxide purifier, and a downstream oxygen sensor that is disposed downstream of the nitrogen oxide purifier. An abnormality determination criterion is set in accordance with the exhaust gas amount of the internal-combustion engine wherein the criterion is equivalent to a time period until the output of the downstream oxygen density sensor is read since the output of the upstream oxygen density sensor is changed to rich after the air-fuel ratio of the exhaust gas was over from lean to rich. Any abnormality of the nitrogen oxide purifier is determined when the output of the downstream oxygen density sensor has been changed to rich before the time period represented by the criterion elapses.
摘要:
An air-fuel ratio control system for an engine for controlling an amount of a fuel mixture to be delivered into a combustion chamber so that an air-fuel ratio of the fuel mixture attains a target air-fuel ratio performs selecting one of a plurality of predetermined target air-fuel ratios according to engine operating conditions, controlling an amount of a fuel mixture so as to attain a selected target air-fuel ratio, and changing a speed at which the target air-fuel ratio is changed from one to another ratio higher with an increase in deviation of the other target air-fuel ratio from the one target air-fuel ratio.
摘要:
A throttle valve control system for an internal combustion engine which controls an opening of a throttle valve of the engine so that the opening coincides with a target opening. A regulation value of a change amount of the throttle valve opening is set according to at least a temperature parameter indicative of a temperature of the engine. The target opening is set within a range defined by the regulation value. An upper limit value and a lower limit value of the regulation value is set according to the temperature parameter, and a transition control is performed wherein the regulation value is set according to an elapsed time period after start of the engine so as to change from the lower limit value to the upper limit value.
摘要:
A control system for an internal combustion engine in which fuel containing alcohol is used. In the control system, a maximum opening of a throttle valve of the engine is set, and a target opening of the throttle valve is set to a value which is equal to or less than the maximum opening. An opening of the throttle valve is controlled so as to coincide with the target opening. The maximum opening is according to a concentration parameter indicative of a concentration of alcohol in the fuel, a temperature parameter indicative of a temperature of the engine, and a number of ignitions performed after start of the engine.
摘要:
The invention relates to an apparatus for diagnosing thermostat trouble in an engine cooling system comprising a thermostat which works to open a valve to make a cooling water flow through a radiator when the cooling water temperature for an engine becomes more than a predetermined temperature, or to close the valve to make the cooling water bypass a radiator when this temperature becomes less than the predetermined temperature. The apparatus comprises means for calculating a radiation heat amount from a radiator received by the cooling water for the engine and means for determining whether the thermostat trouble has occurred based on the radiation heat amount calculated by the means for calculating the radiation heat amount.
摘要:
A failure detection system for detecting an operational failure of a rack and pinion type of hydraulically controlled power steering system which employs a power cylinder to assist the driver in manipulating front wheels of the vehicle by utilizing hydraulic pressure applied to a steering gear connected to the front wheels utilizes a pressure switch for detecting a specified level of oil pressure provided by the power cylinder to be at operational failure when the vehicle speed remains higher than a specified speed for a specified time period, the pressure switch detects the specified level of hydraulic pressure.