New High Quality Diesel Nozzle DLLA145P574 for Injection Nozzle Diesel Engine Parts 0 433 171 435 0433171435

Diesel injector nozzle as the core component of diesel engine fuel injection system, its working condition is directly related to the engine power, fuel consumption and emissions. In the complex and harsh working environment, the fuel nozzle is very prone to various types of failure, accurate analysis of these failures is to ensure that the normal operation of the engine is a key link.

Clogging Failure
Causes: poor fuel quality is the primary cause, poor quality diesel fuel contains a large number of impurities, water and gum. Impurity particles in the nozzle holes gradually accumulate, water and fuel reaction to generate corrosive substances to aggravate the blockage; long-term use, the injector internal carbon will migrate to the nozzle holes. In addition, if the diesel fuel filter maintenance is not appropriate, the failure of the filter element can not effectively filter impurities, will make more foreign matter into the fuel nozzle.
Performance: at the beginning of the blockage, the engine power is slightly reduced, the color of the exhaust smoke becomes darker, the idle speed is slightly shaking. As the plugging intensifies, the fuel atomization becomes worse, the amount of fuel injected is reduced, the engine starting difficulties, acceleration is weak, and even frequent stalling, tailpipe emissions seriously exceed the standard, black smoke rolls.
Diagnosis: Visual inspection of the fuel nozzle nozzle, if you find black carbon or fine particles attached, you can basically judge the existence of clogging. Using professional flow test equipment, compared with normal injectors, the fuel flow of the blocked nozzle is obviously low.

Wear failure
Causes: Nozzle needle valve and valve seat in the high-frequency opening and closing action, mutual friction leads to surface wear. Tiny hard particles in the fuel inclusions, like sandpaper to accelerate the wear process; high-temperature environment so that the needle valve and valve seat material performance decline, toughness is reduced, more susceptible to damage; in addition, if the injection pressure is too high or unstable, beyond the design range, will also exacerbate the wear and tear.
Performance: After the needle valve is worn, the seal is not tight, and the fuel dripping phenomenon occurs. When the engine starts, it is difficult to start because of too much fuel in the cylinder, accompanied by thick black smoke; during operation, the idle speed is unstable, the speed fluctuates greatly, the fuel consumption increases sharply, and the power output is weak.
Diagnosis: disassemble the injector, observe the needle valve head and seat sealing surface, if there are obvious scratches, pockmarks, that is, wear marks. Through the pressure test, wear the opening pressure of the oil nozzle is reduced, the spray pattern is irregular, scattered rather than uniform fog.

Seal failure
Causes: In addition to the above wear and tear resulting in damage to the sealing surface, sealing gasket aging, hardening, loss of elasticity at high temperatures and high pressures, can not be effectively sealed; installation process, if the tightening torque is not appropriate, too loose will cause leakage, too tight may damage the sealing structure; in addition, the body of the nozzle deformation by the impact of external forces, but also undermines the integrity of the seal.
Performance: The most intuitive manifestation of seal failure is fuel leakage and oil stains on the outside of the injector. When the engine is working, due to fuel leakage, the mixture is too thick, the combustion is not sufficient, the power decreases, the fuel consumption rises, the exhaust gas is pungent, and it may be accompanied by the phenomenon of backfire.
Diagnosis: static holding pressure test, under the specified pressure on the injector holding pressure for a period of time, observe the pressure drop, if the pressure decreases rapidly, indicating the existence of sealing problems. Carefully check the appearance of the sealing gasket with or without damage, deformation, nozzle body with or without cracks and other abnormalities.

Diesel fuel injector nozzle common faults are complex and diverse, maintenance personnel need to comprehensively use a variety of diagnostic methods to accurately identify the root cause of the failure. In the daily maintenance, focus on fuel quality control, standardize filter replacement and other operations to prevent failure. Timely repair of faulty fuel nozzles, in order to ensure that diesel engines continue to operate efficiently, to adapt to the strict requirements of the industry on the reliability of power equipment, and to promote the steady development of related technologies.