What is the reason for the high idle speed of car starting?

The common reason for the high idle speed of Pacific Auto Network is that the throttle is stuck and not closed properly. Idle speed control valve failure; Water temperature sensor failure; Air leakage in the air intake system; Air conditioning switch, power steering gear pressure switch failure, etc. Idle speed of automobile refers to a working state of automobile running. When the engine is idling, it is called idling, that is, the gear of the car is in neutral. A more descriptive word is that the engine is "not working hard".

The common reasons for the high idle speed of the car are that the throttle is stuck and closed loosely; Idle speed control valve failure; Water temperature sensor failure; Air leakage in the air intake system; Air conditioning switch, power steering gear pressure switch failure, etc.

There are many reasons for the high idle speed of the car, but we should know that the ignition, intake and nozzle of the engine determine the combustion of fuel and are also the power source of the engine. If the idle speed is high, check the ignition, air intake and nozzle of the engine.

1. Idle speed control valve failure: The normal idle speed of EFI engine is determined by the idle speed control valve. According to the engine speed, temperature, throttle switch and air conditioning switch, the electronic control unit will increase the intake bypass passage of the idle speed control valve or directly increase the throttle opening, thus increasing the intake air volume and improving the engine idle speed. If there is oil pollution and carbon deposition, the idle speed control valve will jam or the throttle valve will not close normally, which will make the electronic control unit unable to adjust the engine idle speed accurately.

Solution: Check the action sound of idle speed control valve. If there is no action sound, the idle speed control valve is faulty.

2. Air leakage in the air intake system: Under normal circumstances, the air intake must be strictly limited. If the air intake pipe leaks, the air flow sensor can't measure the real air intake, and the electronic control unit can't accurately control the air intake, which leads to the unstable idle speed of the car.

Solution: First, find the leakage point, reseal or replace the relevant parts.

3. Nozzle leakage or blockage: Nozzle leakage or blockage makes it impossible to inject fuel according to the instruction of the electronic control unit, resulting in too rich or too thin mixture, which leads to poor operation of individual cylinders and unstable idle speed.

Solution: Measure the fuel injection quantity of the fuel injector. If the fuel injection quantity exceeds the standard, it means that the fuel injector is leaking.