An investigation was conducted into the effects of wear on the performance of
common-rail fuel injectors, in terms of flow and spray characteristics. The investigation
conducted involved the testing of four used injectors, and the comparison
of the performance of these injectors with that of an identical brand new injector.
The used injectors had deteriorated in different ways, with solenoid wear, mechanical
wear in the body of the injector, and mechanical wear in the upper section of
the injector being identified. All of the manners of deterioration affected the flow
characteristics. The solenoid wear and mechanical wear in the body did not affect
the spray performance, but wear in the upper section of the body and a combination
of wear in the body and solenoid did affect spray performance. A correlation
was developed between the spray penetration of the new injector and the spray
theories according to Dent and Hiroyasu
