What is the reason for the unstable idle speed of Buick Excelle?

The reasons for Buick Excelle's high idle speed are: idle speed control valve failure, dirty throttle, stuck throttle, air leakage in intake system, battery power failure, air switch on, low water temperature, mismatch after cleaning throttle, etc. It is recommended to contact the local 4S shop for inspection and maintenance.

1. Air leakage in air intake system

In general, 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 and reseal or replace the relevant parts.

2. The fuel injector leaks or is blocked.

Leakage or blockage of the fuel injector prevents it from injecting fuel according to the instruction of the electronic control unit, resulting in too rich or too thin mixture, which leads to poor operation of the single cylinder and unstable idle speed.

Solution: Measure the fuel injection quantity of the fuel injector. If the injection quantity exceeds the standard, the injector drips oil.

3. Idle speed control valve failure

The normal idle speed of EFI engine is determined by idle speed control valve. According to the engine speed, temperature and the signal that the throttle switch has been switched at idle speed, the electronic control unit opens the air intake bypass or directly increases the throttle opening of the idle control valve, thereby increasing the air intake and improving the engine idle speed. If there is oil stain or carbon deposit, the idle speed control valve will be stuck or the throttle valve will be closed improperly, resulting in that the electronic control unit cannot accurately adjust the engine idle speed.

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

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