What should I do if the car is idling too fast?

Poor idle speed is one of the most common engine faults. Poor idle speed includes unstable idle speed, idle stall, herbal tea, poor idle speed and poor train idle speed. The cause of poor idle speed is often a combination of many reasons. In the process of solving problems and problems, we should analyze the reasons for failure according to the specific manifestations of defects. The engine starts normally, but the idle speed of the cold car or train is unstable, and the idle speed is too low, which is easy to stall. Air intake system leaks. Fuel pressure is too low. The air filter is clogged. The fuel injector has poor fuel injection, oil leakage or blockage. Improper idle speed adjustment. Idle speed adjusting device can't work normally. The air flow meter is faulty. Cylinder compression pressure is too low. Perform fault self-diagnosis and check the fault code.

Check whether the idle speed adjusting device works normally. Disconnect the idle control wire connector. If the engine speed is constant and the idle speed control device or control circuit is defective, the circuit must be repaired or the idle speed control device must be replaced. When idling, please listen carefully to the working sound of each cylinder injector. If the working sound of the injectors in each cylinder is uneven, disassemble, clean or replace the injectors in each cylinder. When the fuel pressure is too low, check the oil pressure regulator, electric fuel pump and gasoline filter. Adjust the engine idle speed according to the specified procedure. Check whether Hebei flat air flowmeter is stuck. If it is defective, it should be replaced. Check the clearance of regulating valve.

When the engine is idling, the idle speed control system will continuously monitor the engine speed and compare it with the target speed in the current engine state. When the engine idling fluctuates and deviates from the set target speed, the output control pulse will generate the action of the idling control actuator to adjust the engine idling to the set target speed range. The engine speed sensor provides the engine speed signal when the engine is idling. Using throttle position sensor to provide throttle closing signal is the basic signal to judge whether the engine is in idle state. It is judged that the engine is in idle working state, and the idle control program is entered. The air conditioner switch that provides the air conditioner blocking signal will only enter the engine speed feedback idle speed stability control when the air conditioner is not used.

Although the engine is in the throttle closed position, when the engine drives a certain load to work at high speed, the output control signal makes the idle speed control actuator act, which increases the idle speed of the engine to a specific value. When using automobile air conditioner, battery loss, etc. The idle speed control system makes the engine run at high idle speed through high idle speed. Ensure that the air conditioning system works normally when the engine is idling, and supply power to the battery in time. If there is a fault code, please find the cause and location of the fault according to the displayed fault code. Check the pipe joint, vacuum hose, exhaust gas recirculation system and fuel evaporation recovery system of the air intake system for air leakage. Engine idling stability control is actually speed feedback control. The microcomputer memory stores the most stable idle parameters of the engine in different states.