Question 1

When forward leakage from a nozzle is being checked, which of the following is being evaluated?

Accepted Answer

A) NOP. 
B) Nozzle-valve seat sealing. 
C) Nozzle valve-to-nozzle body clearance. 
D) Injector spring tension. 
A) NOP. 
B) Nozzle-valve seat sealing. 
C) Nozzle valve-to-nozzle body clearance. 
D) Injector spring tension. B

Question 2

What is the purpose of a slight amount of fuel leakage around the nozzle valve and into the nozzle spring chamber?

Accepted Answer

A) To detect a defective nozzle. 
B) To lubricate the nozzle valve. 
C) To prevent excess fuel delivery. 
D) To cool the valve spring and seat. 
A) To detect a defective nozzle. 
B) To lubricate the nozzle valve. 
C) To prevent excess fuel delivery. 
D) To cool the valve spring and seat. B

Question 3

Technician A says a closed hydraulic nozzle allows combustion gases to mix with fuel inside the nozzle. Technician B says a closed nozzle has no fuel return line back to the fuel tank. Who is correct?

Accepted Answer

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

Question 4

A blocked fuel return line from a nozzle holder could eventually result in which one of the following conditions?

Accepted Answer

A) A worn-out nozzle holder. 
B) Over-fueling the engine. 
C) Excessive spray-in pressures. 
D) Engine stalling. 
A) A worn-out nozzle holder. 
B) Over-fueling the engine. 
C) Excessive spray-in pressures. 
D) Engine stalling.

Question 5

What encloses the nozzle assembly and contains a fitting or passageway connecting the high-pressure injection line to the nozzle valve?

Accepted Answer

A) Mechanical nozzle holder" 
B) Hydraulic nozzle holder" 
C) Pintle 
D) Backleak banjo" 
A) Mechanical nozzle holder" 
B) Hydraulic nozzle holder" 
C) Pintle 
D) Backleak banjo"

Question 6

Fuel leakage from the nozzle tip is called:

Accepted Answer

A) back leakage" 
B) forward leakage" 
C) nominal leakage 
D) bias leakage" 
A) back leakage" 
B) forward leakage" 
C) nominal leakage 
D) bias leakage"

Question 7

Which of the following is a likely cause of excessive back leakage from a fuel nozzle?

Accepted Answer

A) Excessive clearance between the needle valve and nozzle body 
B) Excessive spring pressure. 
C) Worn nozzle orifices. 
D) Needle valve-to-needle seat leakage. 
A) Excessive clearance between the needle valve and nozzle body 
B) Excessive spring pressure. 
C) Worn nozzle orifices. 
D) Needle valve-to-needle seat leakage.

Question 8

When evaluating injector nozzles, a technician notes that the nozzle opening pressure is at 70-90% of minimum specification. Technician A says that this will result in the use of additional fuel. Technician B says that this will result in nozzle dribble. Who is right?

Accepted Answer

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

Question 9

Two technicians are describing testing nozzle spray patterns. Technician A says that disconnect the high-pressure fuel line, then cap the nozzle fuel line inlet fittings by using protective plastic caps. Technician B says that you set up the nozzle pop tester by filling it with number 1 diesel fuel. Who is right?

Accepted Answer

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

Question 10

Technician A says that a pintle nozzle uses a single, large spray hole and is used only in DI (Direct Injection) combustion chambers. Technician B says that fuel spray from a single opening pintle nozzle at low pressure produces poor atomization compared to multi-orifice nozzles. Who is right?

Accepted Answer

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

Question 11

What type of nozzle valve seals the nozzle tip when the valve is seated?

Accepted Answer

A) Closed injector" 
B) Open injector" 
C) Controlled injector 
D) Limited injector" 
A) Closed injector" 
B) Open injector" 
C) Controlled injector 
D) Limited injector"

Question 12

Two technicians are describing testing nozzle spray patterns. Technician A says that the spray should originate from each orifice, and the spray pattern from each orifice can be a different size and shape Technician B says to purge the nozzle tester of air by pumping the handle several times until clean fluid appears from the high-pressure line. Who is right?

Accepted Answer

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

Question 13

What kind of nozzle, identified by the cone-shaped nozzle body at the injector tip, has an injection rate-shaping feature that reduces the amount of fuel injected during the early stages of injection?
Multi-orifice nozzle

Accepted Answer

A) Throttle nozzle" 
B) Multi-orifice nozzle" 
C) Rate shaper nozzle 
D) Venturi nozzle" 
A) Throttle nozzle" 
B) Multi-orifice nozzle" 
C) Rate shaper nozzle 
D) Venturi nozzle"

Question 14

Which type of nozzle is used by a DI combustion chamber?

Accepted Answer

A) Pintle. 
B) Open. 
C) Multi-orifice. 
D) Pencil. 
A) Pintle. 
B) Open. 
C) Multi-orifice. 
D) Pencil.

Question 15

Two technicians are describing safety when testing fuel injectors. Technician A says that the pressure from nozzle testers is high enough to penetrate skin, which can cause blood poisoning. Technician B says that you must never allow hands or skin to get near the tip of an injector nozzle and always wear eye protection. Who is right?

Accepted Answer

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

Question 16

What type of injector is used in a DI (Direct Injection) diesel engine?

Accepted Answer

A) Pintle" 
B) Multi-orifice" 
C) Single-orifice 
D) Poppet" 
A) Pintle" 
B) Multi-orifice" 
C) Single-orifice 
D) Poppet"

Question 17

Technician A says a closed hydraulic nozzle allows combustion gases to mix with fuel inside the nozzle. Technician B says a closed nozzle has no fuel return line back to the fuel tank. Who is correct?

Accepted Answer

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

Question 18

Which of the following conditions is caused by a weak nozzle spring?

Accepted Answer

A) Higher NOP only. 
B) Higher NOP and slightly retarded timing. 
C) Nozzle chatter. 
D) Lower NOP. 
A) Higher NOP only. 
B) Higher NOP and slightly retarded timing. 
C) Nozzle chatter. 
D) Lower NOP.

Question 19

Which of the following emissions would increase the most if a nozzle opening orifice were to become larger because of wear?

Accepted Answer

A) Carbon monoxide (CO)." 
B) Particulate matter (PM)." 
C) Carbon dioxide (CO2). 
D) Oxides of nitrogen (NOx)." 
A) Carbon monoxide (CO)." 
B) Particulate matter (PM)." 
C) Carbon dioxide (CO2). 
D) Oxides of nitrogen (NOx)."

Question 20

Most multi-orifice nozzles are calibrated to an NOP (Nominal Opening Pressure) of between:

Accepted Answer

A) 1,300 and 2,500 psi 
B) 2,300 and 4,500 psi 
C) 4,300 and 7,500 psi 
D) 3300 and 5 500 psi" 
A) 1,300 and 2,500 psi 
B) 2,300 and 4,500 psi 
C) 4,300 and 7,500 psi 
D) 3300 and 5 500 psi"

When forward leakage from a nozzle is being checked, which of the following is being evaluated?

What is the purpose of a slight amount of fuel leakage around the nozzle valve and into the nozzle spring chamber?

Technician A says a closed hydraulic nozzle allows combustion gases to mix with fuel inside the nozzle. Technician B says a closed nozzle has no fuel return line back to the fuel tank. Who is correct?

A blocked fuel return line from a nozzle holder could eventually result in which one of the following conditions?

What encloses the nozzle assembly and contains a fitting or passageway connecting the high-pressure injection line to the nozzle valve?

Fuel leakage from the nozzle tip is called:

Which of the following is a likely cause of excessive back leakage from a fuel nozzle?

When evaluating injector nozzles, a technician notes that the nozzle opening pressure is at 70-90% of minimum specification. Technician A says that this will result in the use of additional fuel. Technician B says that this will result in nozzle dribble. Who is right?

Technician A says that a pintle nozzle uses a single, large spray hole and is used only in DI (Direct Injection) combustion chambers. Technician B says that fuel spray from a single opening pintle nozzle at low pressure produces poor atomization compared to multi-orifice nozzles. Who is right?

What type of nozzle valve seals the nozzle tip when the valve is seated?

What kind of nozzle, identified by the cone-shaped nozzle body at the injector tip, has an injection rate-shaping feature that reduces the amount of fuel injected during the early stages of injection? Multi-orifice nozzle

Which type of nozzle is used by a DI combustion chamber?

What type of injector is used in a DI (Direct Injection) diesel engine?

Technician A says a closed hydraulic nozzle allows combustion gases to mix with fuel inside the nozzle. Technician B says a closed nozzle has no fuel return line back to the fuel tank. Who is correct?

Which of the following conditions is caused by a weak nozzle spring?

Which of the following emissions would increase the most if a nozzle opening orifice were to become larger because of wear?

Most multi-orifice nozzles are calibrated to an NOP (Nominal Opening Pressure) of between:

Introduction to Diesel Engines

Diesel Engine Emissions

Cylinder Blocks and Crankshafts

Cylinder Components

Cylinder Heads and Valve Train Mechanisms

Diesel Engine Cooling and Lubrication Systems

Diesel Fuel and Low Pressure Fuel Systems

Functions of High Pressure Fuel Systems

Governors and Electronic Control Systems

Heui Injection Systems

Common Rail Fuel Systems

Air Induction and Crankcase Ventilation Systems

Fixed Geometry and Wastegated Turbochargers

Variable Geometry and Series Turbochargers

Exhaust Gas Recirculation

Exhaust Aftertreatment Systems

On Board Diagnostics

Filters

Exam 11: Hydraulic Nozzles

When forward leakage from a nozzle is being checked, which of the following is being evaluated?

What is the purpose of a slight amount of fuel leakage around the nozzle valve and into the nozzle spring chamber?

Technician A says a closed hydraulic nozzle allows combustion gases to mix with fuel inside the nozzle. Technician B says a closed nozzle has no fuel return line back to the fuel tank. Who is correct?

A blocked fuel return line from a nozzle holder could eventually result in which one of the following conditions?

What encloses the nozzle assembly and contains a fitting or passageway connecting the high-pressure injection line to the nozzle valve?

Fuel leakage from the nozzle tip is called:

Which of the following is a likely cause of excessive back leakage from a fuel nozzle?

When evaluating injector nozzles, a technician notes that the nozzle opening pressure is at 70-90% of minimum specification. Technician A says that this will result in the use of additional fuel. Technician B says that this will result in nozzle dribble. Who is right?

Technician A says that a pintle nozzle uses a single, large spray hole and is used only in DI (Direct Injection) combustion chambers. Technician B says that fuel spray from a single opening pintle nozzle at low pressure produces poor atomization compared to multi-orifice nozzles. Who is right?

What type of nozzle valve seals the nozzle tip when the valve is seated?

What kind of nozzle, identified by the cone-shaped nozzle body at the injector tip, has an injection rate-shaping feature that reduces the amount of fuel injected during the early stages of injection? Multi-orifice nozzle

Which type of nozzle is used by a DI combustion chamber?

What type of injector is used in a DI (Direct Injection) diesel engine?

Technician A says a closed hydraulic nozzle allows combustion gases to mix with fuel inside the nozzle. Technician B says a closed nozzle has no fuel return line back to the fuel tank. Who is correct?

Which of the following conditions is caused by a weak nozzle spring?

Which of the following emissions would increase the most if a nozzle opening orifice were to become larger because of wear?

Most multi-orifice nozzles are calibrated to an NOP (Nominal Opening Pressure) of between:

Introduction to Diesel Engines

Diesel Engine Emissions

Cylinder Blocks and Crankshafts

Cylinder Components

Cylinder Heads and Valve Train Mechanisms

Diesel Engine Cooling and Lubrication Systems

Diesel Fuel and Low Pressure Fuel Systems

Functions of High Pressure Fuel Systems

Governors and Electronic Control Systems

Heui Injection Systems

Common Rail Fuel Systems

Air Induction and Crankcase Ventilation Systems

Fixed Geometry and Wastegated Turbochargers

Variable Geometry and Series Turbochargers

Exhaust Gas Recirculation

Exhaust Aftertreatment Systems

On Board Diagnostics

Filters