What happened when the car suddenly stopped idling?

1, automobile battery voltage is low; Specific detection method: test the battery voltage with a voltage range of three meters. If it is lower than 10V, it is recommended to replace it. If it is around 1 1V, it is barely used; Be prepared to be replaced. 12V or more is ok.

2. Check whether it is caused by carbon deposition; If driving around 20000KM, check and clean the throttle.

3. Check, test and replace the spark plug.

4. The control unit receives an error signal and sends an error command, which leads to inaccurate idle intake control of the engine and abnormal engine combustion.

5. Failure of idle air actuator leads to inaccurate idle air control.

Influence of idle speed on gasoline engine;

1, economy

According to statistics, because the engine often needs to work at idle speed, about 30% of the fuel consumption of urban motor vehicles is at idle speed. Therefore, it is very important to reduce idle fuel consumption, which is also the requirement of idle speed control.

The main measure to reduce idle fuel consumption is to reduce idle speed. Foreign research shows that 100 r// every idle speed reduction in Min Min is equivalent to running one mile per gallon of gasoline. This requires that the engine speed should not deviate too much from the ideal idle speed when it is disturbed by the outside world.

2. Emissions

When the gasoline engine is idling, there will be a lot of residual exhaust gas in the cylinder. In order to ensure the combustion stability, it is necessary to add rich mixture, so the combustion is incomplete and a large number of harmful emissions of CO and HC are produced.

Experiments show that the lower the idle speed, the more obvious the dilution effect of exhaust gas, which will further increase the emission concentration of CO and HC, so increasing the idle speed is beneficial to reduce the emission of CO and HC. Relevant data and tests show that when the idle speed of automobile engine is increased from 700 rpm to 800 rpm, CO decreases 10% and HC emission decreases 15%.

According to the comprehensive fuel economy and exhaust emission law, the goal of idle speed control of gasoline engine should be to keep the idle speed running smoothly and at low speed, and to reduce CO and HC emissions as much as possible. Therefore, in order to meet the increasingly stringent emission regulations, it is particularly important to reduce the idle speed as much as possible and keep the idle speed stable. This is a big problem faced by the majority of engine electronic control researchers at home and abroad.

Influence of idle speed on diesel engine;

1, launch

Due to the low compression temperature and pressure, poor fuel atomization, uneven formation of mixed gas, insufficient combustion and poor emission performance when the diesel engine is idling. At idle speed and light load, HC and particulate emissions are high. Therefore, improving the idling performance of diesel engine is of great significance to improve its emission performance index.

2. Mobility and comfort

The instability of vehicle diesel engine at idle speed leads to the fluctuation of diesel engine output torque, which causes torsional vibration of the whole transmission system. This phenomenon that the vehicle vibrates back and forth at low frequency (below 5Hz) is called vehicle surge, which not only causes vehicle body vibration, worsens vehicle handling performance and reduces vehicle comfort, but also produces loud noise and affects the life of transmission system.

The unstable operation of diesel engine will also produce the up-and-down vibration of the vehicle. Due to the reaction of the drive system, the up-and-down movement of the vehicle will cause the vehicle to bump back and forth, which has a great influence on the ride comfort. In addition, it is difficult for diesel engine to run stably in some low-speed areas, which is easy to cause the phenomenon of engine speed soaring, and may also cause stall under the action of external load, which has a great impact on vehicle handling performance.

3. Other performances

Idle performance will also affect other performance of diesel engine. The working range of medium and low speed diesel engines is narrow. When the idle speed is unstable, it is necessary to increase the idle speed to improve the idle speed stability, thus further narrowing the working speed range of the diesel engine, which will worsen the fuel economy of the engine and affect the matching between the engine and the transmission system.

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