Exam 13: Common Rail Fuel Systems

The electric current supplied to Delphi's Multec solenoid CR injectors is at:

Two technicians are describing the Delphi Multec injector. Technician A says that the spindle valve used by Delphi nozzles is a servo-hydraulic actuator that uses the principles of hydraulic balance to rapidly open and close. Technician B says that the control valve also regulates the operation of a hydraulically balanced nozzle valve. Who is right?

Technician A says that faster-responding piezoelectric injectors are best suited for use in light-duty CR engines. Technician B says that engine speeds of automotive diesel do not require the piezoelectric injector's higher number of injection events. Who is correct?

Technician A says that a CR engine can vary the injection pressure, timing, and injection rate shape for each injector. Technician B says that the injection pressure is the same for all injectors in CR engines, and injectors can perform multiple injection events during each combustion cycle. Who is correct?

Consider a non-amplified CR injector. If the injection control valve cannot close properly due to dirt or erosion of the valve seat, what is the most common result?

The CRS1, which had limited use in Europe only, uses a single spring to return the armature to a resting position, whereas the CRS2 uses:

While two technicians are discussing the purpose of a second electrical control valve, which regulates fuel volume supplied to the inlet of the high-pressure pump, Technician A says the VCV helps reduce fuel consumption. Technician B says the VCV is needed to reduce emissions. Who is correct?

The Siemens CR injector uses a conventional six-hole nozzle valve that opens inward when the hydraulic balance of the nozzle valve is:

Which of the following is NOT a strategy that can be used to identify faults on common rail systems?

While two technicians are discussing the purpose of a second electrical control valve, which regulates fuel volume supplied to the inlet of the high-pressure pump, Technician A says the VCV helps reduce fuel consumption. Technician B says the VCV is needed to reduce emissions. Who is correct?

Injector adaptation to compensate for wear and deterioration is performed by an algorithm called:

Which of the following terms refers to a control system that multiplies a small mechanical force or movement into a much greater force or movement?

Technician A says that dirt bypassing the filter on some CR systems can cause an injector to stick open and continuously fuel a cylinder. Technician B says that any dirt particles may potentially damage the injector, but they would not allow an injector to full-fuel or cause the engine to run away. Who is correct?

Which Bosch CR system requires certified insulated gloves when working on the system with the ignition key in the On position?

Which of the following is the most likely cause of excessive fuel return from the cylinder head of a CR engine?

Technician A says that servo-hydraulic injector actuators use a small amount of control valve movement to control larger, more powerful, and faster-acting hydraulic forces. Technician B says that control valves that use piezoelectric technology are the only actuators capable of servo action. Who is correct?

At which stage of the Siemens injector operation does fuel pressurized by the high-pressure pump enter the fuel rail and is supplied to each injector fitting?

The spindle valve used by Delphi nozzles is a ____ type of actuator that uses principles of hydraulic balance to open and close rapidly.

When performing a back leakage test on a CR engine with CRI2 injectors, excessive fuel flow from the fuel return line was measured from the cylinder head. Which of the following conditions is most likely the cause?

Each Delphi injector contains (a) laser printed: