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Why Common Rail Fuel Injectors Fail

Posted on 5/4/2016 10:05:05 AM

Common rail systems is an advanced diesel technology which operated at pressures around 4 times that of traditional diesel injection systems.Meanwhile it is equipped with much tighter part clearances and tolerances.Because of this,it brings much greater power, efficiency, and cleaner operation.

Injectors is an important component in this common rail diesel fuel injection systems.Even one tiny problem of injector will cause costly loss to the systems.In order to help you to avoid this loss,first of all the common rail parts manufacturers - China Balin Parts Plant will introduce two primary cause of common rail injectors failure:diesel fuel contamination and improper fuel injector installation.

1.Diesel fuel contamination
As we know,the control valve assembly is an important component in the common rail injector.In this assembly, fuel under very high pressure passes through an orifice, which is sealed by a check ball around 1mm in diameter.Here you could see a new control valve body surface is pictured in Figure 1. Note the uniform grinding of the orifice.If there is any contamination from water or other debris,it will directly effect on the orifice and can quickly lead to a poor seal between the valve and the check ball.It will cause poor injector performance including: starting issues, poor fuel economy and performance, and rough running.Figure 2 presents two examples of control valve bodies which have had check ball seat erosion. Figure 3 is an example of a control valve body and plunger which have been exposed to water.

Because of the condensation of outside air in the vehicle fuel tank or bulk fuel storage,water can be found in diesel fuel.If attention is not paid to the repairing,debris will also come into the fuel systems,flowing through the system from deposits in the fuel tank or from other degrading engine parts. When replacing filters always use a micron rating equal to the OEM recommendation and keep up with scheduled filter maintenance.

Pictured in Figures 4 and 5 is a control valve assembly fuel inlet which has been completely blocked by small metal debris. The fuel will be limited or completely restricted to the injector.Figure 6 is the needle from an injector nozzle which has metallic debris embedded into the tip. Either instance will cause the injector nozzle to remain open, resulting in smoke, knocking, misfire, and no-start conditions along with the potential to severely damage the piston and / or cylinder. Following recommended maintenance procedures and intervals by common rail parts specialist - China Balin Parts Plant can help eliminate these occurrences.

2.improper fuel injector installation.
The improper injector installation includes missing or improperly installed seal rings or nozzle washers and incorrect injector torque.It will cause poor injector performance, misfires, starting issues, and poor fuel economy with black smoke.Be aware of the nozzle washer falling off of the injector or not properly seating during installation.Be sure the prior nozzle washer is not in the cylinder when installing a new injector. A missing or incorrectly installed nozzle washer will allow combustion leakage past the nozzle washer and will be evidenced by excessive combustion residue on the injector when removed. Also, seal rings can roll out of their grooves during installation. On 5.9L injectors,it's very important to install the fuel inlet stud properly.For injectors where electrical connectors are attached to stator studs, incorrect torque of the connectors can result in engine misfires and stator damage.

3.How to Avoid Fuel Injector Failure
No matter which components of fuel systems you want to replace,it is important to analyze what caused the failure of the parts you are replacing.You need to always replace fuel and air filters as well as check the quality of fuel coming from the fuel tank when undertaking these repairs.Fuel systems showing characteristics of fuel contamination require a complete inspection and, if needed, replacement of components which may still contain contamination.If this is not doen correctly,it will also cause subsequent failure of newly installed injectors.




common rail injector

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