Question 1

Which diesel engine manufacturer is noted for the fact that some of their fuel subsystems are entirely under suction?

Accepted Answer

A)  Caterpillar 
B)  Cummins 
C)  Detroit Diesel 
D)  Mack Trucks 
A)  Caterpillar 
B)  Cummins 
C)  Detroit Diesel 
D)  Mack Trucks

Question 2

What device is used to sense the presence of water within a fuel filter and alert the driver?

Accepted Answer

A)  Thermistor 
B)  WIF sensor 
C)  Potentiometer 
D)  CTS sensor 
A)  Thermistor 
B)  WIF sensor 
C)  Potentiometer 
D)  CTS sensor

Question 3

When a leak is identified in an aluminum fuel tank, what do most manufacturers recommend?

Accepted Answer

A)  fill tank with water and weld 
B)  steam tank, fill with nitrogen and weld 
C)  repair with silicone 
D)  replace tank 
A)  fill tank with water and weld 
B)  steam tank, fill with nitrogen and weld 
C)  repair with silicone 
D)  replace tank

Question 4

A small quantity of water is drained from a water separator equipped with a WIF sensor that has produced no service alert. Immediately after, a WIF alert is signaled. What should you do first?

Accepted Answer

A)  Replace the water separator 
B)  Replace the WIF sensor 
C)  Check the fuel tanks for water 
D)  Clean the WIF probes 
A)  Replace the water separator 
B)  Replace the WIF sensor 
C)  Check the fuel tanks for water 
D)  Clean the WIF probes

Question 5

When priming a new secondary filter, which method do most OEMs prefer you use?

Accepted Answer

A)  pressurize the fuel tanks 
B)  a hand, electric, or integral primer pump 
C)  pour fuel only into filter inlet ports 
D)  pour fuel only into filter outlet port 
A)  pressurize the fuel tanks 
B)  a hand, electric, or integral primer pump 
C)  pour fuel only into filter inlet ports 
D)  pour fuel only into filter outlet port

Question 6

Which of the following is NOT generally considered to be a desirable feature specified to a truck fuel tank?

Accepted Answer

A)  aluminum construction 
B)  cylindrical shape 
C)  temperature insulated 
D)  located in airflow 
A)  aluminum construction 
B)  cylindrical shape 
C)  temperature insulated 
D)  located in airflow

Question 7

When a single pick-up tube is used on a pair of cylindrical fuel tanks mounted either side of a truck frame, which of the following is required?

Accepted Answer

A)  auxiliary pump 
B)  two return lines 
C)  two transfer pumps 
D)  crossover pipe 
A)  auxiliary pump 
B)  two return lines 
C)  two transfer pumps 
D)  crossover pipe

Question 8

What pumping principle is used by hand-actuated priming pumps on most current diesel fuel subsystems?

Accepted Answer

A)  reciprocating plunger 
B)  centrifugal 
C)  gear 
D)  vane 
A)  reciprocating plunger 
B)  centrifugal 
C)  gear 
D)  vane

Question 9

When you are asked to repair weld an aluminum diesel fuel tank, which of the following is recommended?

Accepted Answer

A)  fill with fuel before welding 
B)  fill with water before welding 
C)  steam and fill with nitrogen 
D)  steam and fill with oxygen 
A)  fill with fuel before welding 
B)  fill with water before welding 
C)  steam and fill with nitrogen 
D)  steam and fill with oxygen

Question 10

What do Caterpillar define as the maximum amount of water content in a diesel fuel if it meets their standards for clean fuel?

Accepted Answer

A)  0.0015% 
B)  0.01% 
C)  0.10% 
D)  1% 
A)  0.0015% 
B)  0.01% 
C)  0.10% 
D)  1%

Question 11

In conditions of extreme heat in most diesel fuel systems, what happens to diesel fuel vapors boiled off from the fuel in the fuel tanks?

Accepted Answer

A)  vented to atmosphere 
B)  exit pick-up tube causing vapor lock 
C)  charged to a carbon canister 
D)  create high tank pressures 
A)  vented to atmosphere 
B)  exit pick-up tube causing vapor lock 
C)  charged to a carbon canister 
D)  create high tank pressures

Question 12

In order to prime a typical fuel sub-system with a hand-primer pump that has to be installed into the circuit, where should it ideally be located?

Accepted Answer

A)  close to the pick-up tube 
B)  upstream from the primary filter 
C)  upstream from the transfer pump 
D)  downstream from the secondary filter 
A)  close to the pick-up tube 
B)  upstream from the primary filter 
C)  upstream from the transfer pump 
D)  downstream from the secondary filter

Question 13

When comparing the properties of diesel fuel with water, which of the following is NOT true of diesel fuel?

Accepted Answer

A)  more compressible 
B)  higher lubricity 
C)  lower freeze point 
D)  promotes corrosion 
A)  more compressible 
B)  higher lubricity 
C)  lower freeze point 
D)  promotes corrosion

Question 14

?Technician A says that some diesel post-2007 diesel engines fitted with DPFs use a dosing injector. Technician B says that diesel fuel subsystem charging pressure values can be much higher in engines that use dosing injectors. 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 15

Which of the following is the critical electrical component of a diesel fuel tank sending unit?

Accepted Answer

A)  float 
B)  variable resistor 
C)  thermistor 
D)  low fuel warning light 
A)  float 
B)  variable resistor 
C)  thermistor 
D)  low fuel warning light

Question 16

When testing for fuel subsystem inlet restriction which of the following is recommended?

Accepted Answer

A)  positive pressure gauge reading in inches of water 
B)  positive pressure gauge reading in inches of mercury 
C)  negative pressure gauge reading in inches of mercury 
D)  plumb an air filter restriction gauge into the primary filter pad 
A)  positive pressure gauge reading in inches of water 
B)  positive pressure gauge reading in inches of mercury 
C)  negative pressure gauge reading in inches of mercury 
D)  plumb an air filter restriction gauge into the primary filter pad

Question 17

Technician A says that diesel fuel is potentially explosive and should be handled with great care during refilling operations especially in the heat of summer. Technician B says that refueling diesel fuel tanks while smoking a cigarette is not advisable. 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

Technician A says that the best way to prime a diesel fuel system is to charge shop air pressure to the fuel tank and crank the engine unit it fires. Technician B says that when a fuel subsystem is fitted with an ECM-managed priming pump, this should always be used to prime the engine after a service. 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 19

Which of the following components would NOT be under suction when the engine is running?

Accepted Answer

A)  primary filter 
B)  pickup tube 
C)  fuel tank 
D)  secondary filter 
A)  primary filter 
B)  pickup tube 
C)  fuel tank 
D)  secondary filter

Question 20

Which of the following sensors would least likely be used in a current fuel subsystem?

Accepted Answer

A)  charging pressure sensor 
B)  fuel pressure sensor 
C)  water-in-fuel sensor 
D)  inductive pulse sensor 
A)  charging pressure sensor 
B)  fuel pressure sensor 
C)  water-in-fuel sensor 
D)  inductive pulse sensor

Exam 19: Fuel Subsystems

Which diesel engine manufacturer is noted for the fact that some of their fuel subsystems are entirely under suction?

What device is used to sense the presence of water within a fuel filter and alert the driver?

When a leak is identified in an aluminum fuel tank, what do most manufacturers recommend?

A small quantity of water is drained from a water separator equipped with a WIF sensor that has produced no service alert. Immediately after, a WIF alert is signaled. What should you do first?

When priming a new secondary filter, which method do most OEMs prefer you use?

Which of the following is NOT generally considered to be a desirable feature specified to a truck fuel tank?

When a single pick-up tube is used on a pair of cylindrical fuel tanks mounted either side of a truck frame, which of the following is required?

What pumping principle is used by hand-actuated priming pumps on most current diesel fuel subsystems?

When you are asked to repair weld an aluminum diesel fuel tank, which of the following is recommended?

What do Caterpillar define as the maximum amount of water content in a diesel fuel if it meets their standards for clean fuel?

In conditions of extreme heat in most diesel fuel systems, what happens to diesel fuel vapors boiled off from the fuel in the fuel tanks?

In order to prime a typical fuel sub-system with a hand-primer pump that has to be installed into the circuit, where should it ideally be located?

When comparing the properties of diesel fuel with water, which of the following is NOT true of diesel fuel?

?Technician A says that some diesel post-2007 diesel engines fitted with DPFs use a dosing injector. Technician B says that diesel fuel subsystem charging pressure values can be much higher in engines that use dosing injectors. Who is correct?

Which of the following is the critical electrical component of a diesel fuel tank sending unit?

When testing for fuel subsystem inlet restriction which of the following is recommended?

Technician A says that diesel fuel is potentially explosive and should be handled with great care during refilling operations especially in the heat of summer. Technician B says that refueling diesel fuel tanks while smoking a cigarette is not advisable. Who is correct?

Which of the following components would NOT be under suction when the engine is running?

Which of the following sensors would least likely be used in a current fuel subsystem?

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 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

Common Rail Systems

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

Filters