What is the cause of unstable idle speed of diesel engine?

Engine idling instability, excessive fouling on throttle and air intake, fuel pressure failure, inaccurate ignition advance angle, spark plug and high-voltage line failure, etc.

There is too much dirt on the throttle and air intake. Too much carbon and dirt are deposited in the throttle valve and the surrounding air intake, and the cross-sectional area of the air passage changes, which makes the adjustment unit unable to accurately adjust the idle intake, resulting in too rich or too thin mixture and abnormal combustion. Frequently encountered reasons are: throttle carbon deposition, oil pollution, and carbon deposition at the air intake around the throttle.

Causes of unstable idle speed of diesel vehicles;

1, dirty and worn mechanical parts, incorrect installation, etc. , which leads to the power change of a single cylinder, unbalanced power of each cylinder, unstable idle speed of the engine, abnormal electronic control system of the engine, poor combustion of mixed gas, difficult balance of power of each cylinder, and unstable idle speed of the engine.

2. Too much carbon and dirt are deposited in the throttle valve and the surrounding air intake, and the cross-sectional area of the air passage changes, which makes the control unit unable to accurately control the idle intake, resulting in the mixture being too rich or too thin and abnormal combustion.

3. The fuel pressure is too low, which directly leads to the fog of sprayed oil and poor spray quality. In severe cases, only some oil droplets appear at the oil injection port. The main performance is that the mixture is discharged too thinly, which leads to unstable idle speed and low speed of the engine, often accompanied by fire.