Small partners in the daily use of vehicles in the process of abnormal, we must carefully find a variety of abnormal phenomena before the fault, such as the car after the start of the idle speed is unstable, do not panic at this moment, as long as the car can start, the problem will not be too big, how to troubleshoot this failure?

First of all, check the air intake system of the car, that is, all the air into the cylinder must be entered through the air filter: check whether the intake pipe clip is loose or the connecting hose is broken, whether the intake pipe liner is leaking, and whether the intake pipe is damaged. The fuel injector O-ring has no leakage, check to see if there is any damage cracks, when the air, gasoline steam, combustion exhaust gas should not enter the intake pipe, causing the mixture to be too thick or too thin, so that the engine combustion is not normal, the engine will shake, cold car idle instability or high idle speed.

If the carbon accumulation and dirt of the throttle valve and the surrounding inlet are too much, the cross-section area of the air channel changes, making the control unit unable to accurately control the idle intake volume, resulting in too thick or too thin mixture, and also cause idle instability.

If the fuel injection of the injector is uneven, the fog is not good, the injector is blocked, the fuel pump filter is blocked, the pump oil pressure of the fuel pump is insufficient, the oil inlet pipe is deformed and the oil return pipe is compressed and blocked, it will cause poor atomization, resulting in unstable idle speed and poor acceleration.

If the car travels to a certain number of kilometers, but also check the spark plug, check the ignition system, mileage to a certain number of kilometers, too much carbon in the piston ring groove, piston ring normal wear caused by the gap is too large, piston and cylinder spontaneous combustion loss changed the compression ratio, combustion chamber carbon will also change the compression ratio, serious carbon accumulation will lead to idle instability

Due to improper operation of the stepper motor lost step may also cause abnormal idle speed, at this time you need a professional master to restore the system factory Settings.

The intake system, fuel system, ignition system and engine mechanical failure can all lead to engine idling instability. Not timely elimination will cause more fault phenomena, there are many reasons for idle instability failure, so the investigation of the cause of engine idle instability is a wide range of difficult work. Correct judgment should be made according to the latest test results, theoretical analysis and maintenance experience, and then repair the fault point.

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