What are the main symptoms and causes of fuel injector malfunctions?

Poor fuel atomization: This kind of malfunction will lead to a decrease in diesel engine power, black - smoke emissions, and abnormal operating noise of the machine. This is mainly caused by insufficient fuel injection pressure, wear and carbon deposition of the injection holes, wear of the spring end face, or weakened spring force and other factors.

Needle valve seizure: When this kind of malfunction occurs, the engine power will be reduced, it will shake, and in severe cases, it may not even start. This is usually because the water or acidic substances in diesel cause the needle valve to rust and get stuck, or after the sealing conical surface of the needle valve is damaged, the combustible gas in the cylinder enters the mating surface and forms carbon deposits, making the needle valve unable to move.

Fuel injector nozzle leakage: When the diesel engine temperature is low, it is difficult to start, and white smoke is emitted from the exhaust pipe. As the diesel engine temperature rises, the smoke color turns black, and fuel consumption increases. This is often due to the fact that when the fuel injector is working, the sealing conical surface of the needle valve body is frequently and strongly impacted by the needle valve, and high - pressure fuel is constantly injected from there, resulting in gradual wear or spots on the conical surface.

Excessive fuel return volume: This will lead to a decrease in fuel injection pressure and a delay in fuel injection time, which in turn will cause a decrease in engine power and may even cause the diesel engine to stall. This kind of malfunction is usually caused by severe wear of the needle - valve matching parts, loose fitting between the needle - valve body and the fuel - injector housing, or wear of the valve plate.