Exam 21: Injector Nozzles

What are the functions of a typical hydraulic injector nozzle?

In a running engine with a CR diesel system, what force(s) hold the nozzle needle seated when the actuator is not energized?

Technician A says that after replacing an injector spring on a hydraulic multi-orifice injector, it is good practice to set NOP 75 psi above specification. Technician B says that any time a hydraulic nozzle assembly is reassembled after bench testing, it is good practice to set NOP 150 psi above specification. Who is right?

Which of the following components in a multi-orifice hydraulic injector is constantly exposed to line pressure?

What is the advantage of piezo actuators over solenoid actuators?

When nozzle back leakage is higher than specification, this is usually an indication of:

The highest pressure that a diesel injection circuit is subject to is known as:

What force(s) hold an EHI nozzle needle seated in a standard CR system when the engine is stationary and there is no measurable rail pressure?

If injector valve-to-nozzle body clearance in a multi-orifii injector is greater than specification, which of the following values would increase?

When adjusting a low spring injector nozzle NOP, what should be done to increase opening pressure?

What pressure is dead volume fuel held at in pump-line-nozzle (PLN) diesel fuel systems?