How to adjust the high idle speed of the car

The adjustment of high idle speed of automobile should be carried out under the condition that the automobile is normal in all aspects. Adjust the throttle opening adjusting screw to make the engine turn from low to high, and adjust it repeatedly until the engine runs at the lowest stable speed.

Idle speed adjustment must be carried out under normal conditions, such as normal engine temperature, proper valve clearance, normal ignition system, good sealing of all pipelines, full throttle opening and tight throttle closing. When adjusting, first loosen the throttle opening adjustment screw to make the engine reach the lowest stable speed.

Then screw in the idle speed adjusting screw with a screwdriver, and then slowly unscrew the idle speed adjusting screw when the engine is about to stall, so that the engine can run smoothly and reach a high speed. Then loosen the throttle opening adjustment screw to make the engine speed as low as possible, and then adjust the idle speed adjustment screw to improve the engine speed.

Repeat this process until the throttle opening is minimum and the engine runs at the lowest stable speed. Finally, increase the speed and suddenly close the throttle, so that the engine can still turn without stalling.

Causes of idling of cars

1, 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, throttle switch, air conditioning switch and other signals, the electronic control unit will increase the intake bypass passage of the idle speed control valve or directly increase the throttle opening after calculation, thus increasing the air intake 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.

2. Air leakage in the 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.