Question 1

What is the function of the quill tube used in many diesel CR systems?

Accepted Answer

A)  connects the CR high pressure pump to the rail 
B)  connects the transfer pump to the secondary filter 
C)  vents the fuel tank to atmosphere 
D)  connects the rail high pressure pipes to the EHIs through the cylinder head 
A)  connects the CR high pressure pump to the rail 
B)  connects the transfer pump to the secondary filter 
C)  vents the fuel tank to atmosphere 
D)  connects the rail high pressure pipes to the EHIs through the cylinder head D

Question 2

Technician A says that EHI pressure at the beginning of an injection pulse should be closely equivalent to rail pressure. Technician B says that EHI pressure at the end of an injection pulse will have dropped off significantly. Who is correct?

Accepted Answer

A)  Technician A only 
B)  Technician B only 
C)  Both A and B 
D)  Neither A nor B 
A)  Technician A only 
B)  Technician B only 
C)  Both A and B 
D)  Neither A nor B A

Question 3

How many high pressure pumps are required to fuel a typical inline 6-cylinder, CR-fueled engine?

Accepted Answer

A)  One 
B)  Two 
C)  Three 
D)  Six 
A)  One 
B)  Two 
C)  Three 
D)  Six A

Question 4

What is used to lubricate the high pressure radial piston pumps used on most Bosch CR fuel systems?

Accepted Answer

A)  Fuel 
B)  Isolated oil supply 
C)  Engine lubrication circuit 
D)  Lubriplate 
A)  Fuel 
B)  Isolated oil supply 
C)  Engine lubrication circuit 
D)  Lubriplate

Question 5

?Technician A says that MY 2013 and later Paccar MX engines use a pair of EUPs to supply the common rail with high pressure fuel. Technician B says that Paccar PX engines use a Bosch CR fuel system. Who is correct?

Accepted Answer

A)  ?Technician A only 
B)  ?Technician B only 
C)  ?Both A and B 
D)  ?Neither A nor B 
A)  ?Technician A only 
B)  ?Technician B only 
C)  ?Both A and B 
D)  ?Neither A nor B

Question 6

Technician A says that the first generation of diesel common rail (CR) systems was introduced on small bore diesel engines. Technician B says that CR fuel systems are unable to produce high enough peak pressures to fuel current large bore diesel engines. Who is correct?

Accepted Answer

A)  Technician A only 
B)  Technician B only 
C)  Both A and B 
D)  Neither A nor B 
A)  Technician A only 
B)  Technician B only 
C)  Both A and B 
D)  Neither A nor B

Question 7

What explains why EHIs with Piezo actuators respond faster to energization signals from the injector drivers?

Accepted Answer

A)  mechanical movement at the actuator does not depend on building a magnetic field 
B)  piezoelectric signals travel faster 
C)  piezo actuators are lighter in weight than solenoid actuators 
D)  piezo actuators consume much more electricity than solenoid actuators 
A)  mechanical movement at the actuator does not depend on building a magnetic field 
B)  piezoelectric signals travel faster 
C)  piezo actuators are lighter in weight than solenoid actuators 
D)  piezo actuators consume much more electricity than solenoid actuators

Question 8

What would happen if an EHI used on a Bosch CR fuel system stuck in an open position?

Accepted Answer

A)  Fuel rail pressure would collapse 
B)  Immediate engine shutdown 
C)  Cylinder would overfuel 
D)  Flow limiter would limit fueling 
A)  Fuel rail pressure would collapse 
B)  Immediate engine shutdown 
C)  Cylinder would overfuel 
D)  Flow limiter would limit fueling

Question 9

Technician A says that an advantage of CR-EHIs is that they are less susceptible to problems caused by contaminated fuel than other types of fuel injector. Technician B says that when a CR-EHI fails due to contaminated fuel, the problem can be usually rectified by disassembly, cleaning, and reassembly. Who is correct?

Accepted Answer

A)  Technician A only 
B)  Technician B only 
C)  Both A and B 
D)  Neither A nor B 
A)  Technician A only 
B)  Technician B only 
C)  Both A and B 
D)  Neither A nor B

Question 10

Which of the following best explains why some OEMs state that the high pressure pipes used on CR systems should not be re-used?

Accepted Answer

A)  the line nut hex is easily rounded out 
B)  the engine warranty will voided 
C)  it is more profitable to the OEM to sell as many parts as possible 
D)  the seats deform to seal when initially torqued 
A)  the line nut hex is easily rounded out 
B)  the engine warranty will voided 
C)  it is more profitable to the OEM to sell as many parts as possible 
D)  the seats deform to seal when initially torqued

Question 11

What type of fuel system is used on EPA MY 2010 and later Cummins ISX engines?

Accepted Answer

A)  CAPS 
B)  HPI-TP 
C)  EUI 
D)  XPI 
A)  CAPS 
B)  HPI-TP 
C)  EUI 
D)  XPI

Question 12

What force is used to hold the nozzle valve seated and closed on a typical CR-EHI when the engine is running?

Accepted Answer

A)  Combined spring and hydraulic force 
B)  Combined spring and electrical force 
C)  Spring force only 
D)  Electrical force only 
A)  Combined spring and hydraulic force 
B)  Combined spring and electrical force 
C)  Spring force only 
D)  Electrical force only

Question 13

If the rail pressure limiter valve trips open in a typical CR fuel system, which of the following should be true?

Accepted Answer

A)  rail pressure has exceeded the highest specified system pressure 
B)  an EHI injection pulse is taking place 
C)  actual rail pressure has fallen below desired rail pressure 
D)  an EHI has stuck in the open position 
A)  rail pressure has exceeded the highest specified system pressure 
B)  an EHI injection pulse is taking place 
C)  actual rail pressure has fallen below desired rail pressure 
D)  an EHI has stuck in the open position

Question 14

When a typical CR-EHI is energized by the injector driver, which of the following occurs first?

Accepted Answer

A)  pressure in the valve control chamber rises 
B)  pressure in the valve control chamber collapses 
C)  an injection pulse begins 
D)  an injection pulse 
A)  pressure in the valve control chamber rises 
B)  pressure in the valve control chamber collapses 
C)  an injection pulse begins 
D)  an injection pulse

Question 15

How many pump cylinders are used in a Caterpillar CR system high pressure pump?

Accepted Answer

A)  one for each engine cylinder 
B)  three 
C)  two 
D)  one 
A)  one for each engine cylinder 
B)  three 
C)  two 
D)  one

Question 16

Which of the following best describes the type of pump used with typical Bosch CR fuel systems?

Accepted Answer

A)  Rotary distributor 
B)  In-line plunger 
C)  Radial piston 
D)  Opposed plunger 
A)  Rotary distributor 
B)  In-line plunger 
C)  Radial piston 
D)  Opposed plunger

Question 17

Technician A says that desired rail pressure in a CR fuel system is signaled by the rail pressure sensor. Technician B says that actual rail pressure in a CR fuel system is calculated by the ECM. Who is correct?

Accepted Answer

A)  Technician A only 
B)  Technician B only 
C)  Both A and B 
D)  Neither A nor B 
A)  Technician A only 
B)  Technician B only 
C)  Both A and B 
D)  Neither A nor B

Question 18

What term is used by Caterpillar on their CR EHIs to code their injection quantity calibration data for programming to the ECM?

Accepted Answer

A)  quick response (QR) code 
B)  E-Trim 
C)  Cal code 
D)  Set point 
A)  quick response (QR) code 
B)  E-Trim 
C)  Cal code 
D)  Set point

Question 19

Technician A says that most Bosch CR high pressure pumps are lubricated with diesel fuel. Technician B says that Caterpillar CR high pressure pumps are lubricated with engine oil. Who is correct?

Accepted Answer

A)  Technician A only 
B)  Technician B only 
C)  Both A and B 
D)  Neither A nor B 
A)  Technician A only 
B)  Technician B only 
C)  Both A and B 
D)  Neither A nor B

Question 20

Which of the following components serves as the accumulator in a typical diesel CR fuel system?

Accepted Answer

A)  Hydraulic head 
B)  Rail 
C)  Pump chamber 
D)  Amplifier chamber 
A)  Hydraulic head 
B)  Rail 
C)  Pump chamber 
D)  Amplifier chamber

Exam 30: Common Rail Systems

What is the function of the quill tube used in many diesel CR systems?

Technician A says that EHI pressure at the beginning of an injection pulse should be closely equivalent to rail pressure. Technician B says that EHI pressure at the end of an injection pulse will have dropped off significantly. Who is correct?

How many high pressure pumps are required to fuel a typical inline 6-cylinder, CR-fueled engine?

What is used to lubricate the high pressure radial piston pumps used on most Bosch CR fuel systems?

?Technician A says that MY 2013 and later Paccar MX engines use a pair of EUPs to supply the common rail with high pressure fuel. Technician B says that Paccar PX engines use a Bosch CR fuel system. Who is correct?

Technician A says that the first generation of diesel common rail (CR) systems was introduced on small bore diesel engines. Technician B says that CR fuel systems are unable to produce high enough peak pressures to fuel current large bore diesel engines. Who is correct?

What explains why EHIs with Piezo actuators respond faster to energization signals from the injector drivers?

What would happen if an EHI used on a Bosch CR fuel system stuck in an open position?

Which of the following best explains why some OEMs state that the high pressure pipes used on CR systems should not be re-used?

What type of fuel system is used on EPA MY 2010 and later Cummins ISX engines?

What force is used to hold the nozzle valve seated and closed on a typical CR-EHI when the engine is running?

If the rail pressure limiter valve trips open in a typical CR fuel system, which of the following should be true?

When a typical CR-EHI is energized by the injector driver, which of the following occurs first?

How many pump cylinders are used in a Caterpillar CR system high pressure pump?

Which of the following best describes the type of pump used with typical Bosch CR fuel systems?

Technician A says that desired rail pressure in a CR fuel system is signaled by the rail pressure sensor. Technician B says that actual rail pressure in a CR fuel system is calculated by the ECM. Who is correct?

What term is used by Caterpillar on their CR EHIs to code their injection quantity calibration data for programming to the ECM?

Technician A says that most Bosch CR high pressure pumps are lubricated with diesel fuel. Technician B says that Caterpillar CR high pressure pumps are lubricated with engine oil. Who is correct?

Which of the following components serves as the accumulator in a typical diesel CR fuel system?

Introduction

Hand and Shop Tools, Precision Tools, and Units of Measurement

Personal and Safety Awareness

Engine Basics

History of the Heat Engine

Power

Engine Powertrain Components

Engine Feedback Assembly

Engine Housing Components

Engine Lubrication Systems

Engine Cooling Systems

Engine Breathing

Engine Retarders

Servicing and Maintenance

Engine Removal, Disassembly, Cleaning,

Diesel Engine Run- in and Performance Testing

Chemistry and Combustion

Diesel Fuel Characteristics

Fuel Subsystems

Fuel Injection Basics and Governor Principles

Injector Nozzles

Port-Helix Metering Injection Pumps

Inlet-Metering Rotary Distributor Pumps

Sleeve-Metering Rotary Distributor Pumps

Single-Actuator Eui Systems

Dual-Actuator Eui Systems

Heui Fuel Systems

Electronic Unit Pump Eup Systems

Cummins Hpi-Tp

Amplified Common Rail Systems

Review of Electrical and Electronics Fundamentals

Vehicle Computer Systems

Ests and Siss

Electrical Wiring, Connector Terminal Repair

Multiplexing

The Connected Vehicle

Natural Gas, Propane, and Biodiesel Fuels

High Voltage Electricity

Hybrid and Hydrogen Fuel Cell Drivetrains

Electric Powertrains

Bosch Edc Systems

Caterpillar Engine Management Systems

Cummins Management Systems

Detroit Diesel Electronic Controls Ddec

Navistar Diamond Logic

Paccar Engine Management Systems

Volvo and Mack Engine Management

Emissions Management

Servicing Maintenance of Exhaust Aftertreatment Systems

Failure Analysis

Troubleshooting and Diagnostics

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