Exam 21: Injector Nozzles

?Technician A says that EHIs are ECM switched to open and close. Technician B says that EHIs are opened when pressure in the CR rises to the nozzle opening pressure. Who is correct?

Technician A says that high pressure fuel can exit an injector nozzle at faster than the speed of sound. Technician B says that the most OEMs recommend electrohydraulic injectors (EHIs) to be field serviced using standard shop tools. Who is correct?

When considering EHI operation in a standard CR system while the engine is running but the actuator is not energized which of the following is true?

Technician A says that multi-orifice hydraulic injectors have hard value NOPs. Technician B says that NOPs in electrohydraulic injectors (EHIs) have variable NOPs that are controlled by the ECM. Who is correct?

While bench testing a multi-orifice injector nozzle, it rapidly pulses (chatter) as NOP is achieved. Technician A says that the nozzle seat is defective and should be replaced. Technician B says that nozzle chatter usually occurs only during bench testing. Who is right?

When a multi-orifice injector nozzle is closed, what seals the nozzle assembly from the engine cylinder?

What is required to test the NOP of a hydraulic injector?

When attempting to remove a seized injector spacer washer, which of the following tools would be recommended?

A hydraulic injector nozzle that uses a sacless design is known as:

Which of the following tools can be used to pull a flanged hydraulic injector nozzle from a cylinder head?

What is a typical NOP value of the multi-orifice nozzle used in an EUI (electronic unit injector)?

Which of the following is another way of saying injector bench test fixture?

When multi-orifice nozzles are used in hydromechanical diesel engines, what would be a typical NOP value?

What determines the soft opening and closing values of EHIs in any given moment of engine operation?

Which type of multi-orifice injector nozzle sometimes uses an accumulator in place of a leakoff circuit?

If a 4-stroke cycle diesel engine is run at 2000 rpm, how much real time is required for a single revolution of the engine?

What type of injector nozzles are used with today's direct injected engines?

Identify the nozzle capable of soft opening pressures?

As pressure increases in the injection circuit, what happens to the emitted droplet sizing?

What is the geometric relationship between the sectional area of the nozzle seat, and that of the nozzle pressure chamber known as?