What should I do if the idle speed of Volkswagen LaVida engine is unstable?

1. Check the vacuum tube for air leakage. If there is a vacuum leak, the ECM may increase the fuel injection quantity, resulting in excessive idle speed.

2. Check whether the idle speed control valve works normally. Whether there is carbon deposit stuck and whether the valve body is in good condition.

3. Check whether the throttle valve is closed at idle speed. If it is not closed tightly, check whether the throttle valve is stuck due to carbon deposition or locked too tightly.

4. Check whether the air temperature sensor and water temperature sensor and their circuit signals are normal. If the monitored temperature is higher than the actual temperature of the engine, fuel injection will increase, resulting in excessive idle speed.

5. Check whether the air flow meter (or intake manifold pressure sensor) signal and its circuit are normal.

6. Check whether the air conditioning system, power steering switch and shift switch have signal output or wiring problems when they are not working. If these systems still output signals when they are not working, the idle speed will be too high.

7. Check whether there is any problem with the engine control module or matching settings. If there is any problem, please reset it.

8. Check whether the fuel pressure is too high. If the pressure is too high, the fuel injection quantity will increase, and the idle speed will be too high.

9. Check whether the fuel injector leaks. If the fuel injector leaks oil, it will increase the fuel injection quantity, but the idle speed is too high.

10. Check whether the fuel injection quantity of the fuel injector is within the specified range.

Engine idling performance has a great influence on emissions, fuel consumption and comfort, so engine idling performance is an important index to evaluate engine performance. When idling, the engine is separated from the transmission system and the accelerator pedal is completely released. The engine only overcomes its own resistance and does not output work. Engine idle speed is called idle speed, which cannot be too high or too low. Too high will increase fuel consumption, too low will make the engine idling unstable. The lowest idle speed to ensure the stable operation of the engine is the best idle speed. Generally, the idle speed of automotive diesel engines is 500 ~ 800 rpm, and that of gasoline engines is 700 ~ 1000 rpm.