Deck 10: Governors and Electronic Control Systems

Question 1

Which type of governor senses changes in engine load and automatically adjusts the fuel rate to compensate for load changes?

A)Variable speed.
B)Automotive.
C)Pneumatic.
D)Overspeed.

Answer 1

A

Question 2

The difference between maximum engine speed with a load applied and a no-load speed is often known as _________.

A)speed droop
B)stability
C)underrun
D)overrun

Answer 2

A

Question 3

What type of engine emission is controlled by the air-fuel ratio device?

A)Oxides of nitrogen (NO_x).
B)Carbon monoxide (CO).
C)Particulate matter (PM).
D)Hydrocarbons (HCs).

Answer 3

C

Question 4

Which of the following torque rise and transmission configurations is best used in an automobile?

A)A high torque rise engine with few transmission gear steps.
B)A low torque rise engine with many transmission gear steps.
C)A high torque rise engine with overdrive transmission gear steps.
D)A low torque rise engine with few transmission gear steps.

Question 5

Which of the following features is used to prevent driveline windup or jerking during vehicle deceleration?

A)Load controllers.
B)Air-fuel ratio control device.
C)Isochronous governor.
D)Variable-speed governor.

Question 6

Technician A says that a cam position sensor can sense engine speed and position. Technician B says that a crankshaft position sensor can sense engine speed and position Who is correct?

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

Question 7

While discussing possible causes of a low-power problem in an engine that uses a mechanical governor, Technician A says that weak governor springs can cause the problem. Technician B says that a leaking tube connecting the intake manifold and air-fuel ratio control device can cause the problem. Who is correct?

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

Question 8

Technicians A and B are discussing which engine would be best to use to pull tree stumps from some land on a farm. The choice is between two engines in two different medium-duty pickup trucks. Technician A says the engine with a peak torque of 850 ft-lb (1,152 N·m) and 325 horsepower (242 kW) is ideal for pulling stumps. Technician B says the other truck, with an engine with a peak torque of 650 ft-lb (881 N·m) and 400 horsepower (198 kW) is better. Who is correct?

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

Question 9

Technician A says that a diesel engine needs a governor to prevent a commercial vehicle from wasting fuel. Technician B says that a diesel engine needs a governor to regulate fuel delivery because diesels are very sensitive to slight changes in the amount of fuel injected and can overspeed. Who is correct?

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

Question 10

Which type of governor requires the operator to adjust engine speed when the load that is applied to an engine changes?

A)Variable speed.
B)Limiting speed (LS).
C)Hydraulic.
D)Servo.

Question 11

Which type of governor will be commonly used to control the fueling of a diesel electric generator?

A)Isochronus.
B)Hydraulic.
C)Load limiting.
D)Overspeed.

Question 12

During which one of the following conditions will the tension of the starting spring or governor spring of a mechanical governor usually be greater than flyweight force?

A)During cranking.
B)While the engine is at idle.
C)While the engine is at high idle.
D)While the engine is at rated rpm.

Question 13

Technician A says that any type of governor will always attempt to maintain engine idle speed even if two or three cylinders are misfiring. Technician B says that only a variable-speed governor will compensate for a misfire loss from one or two cylinders and maintain idle speed. Who is correct?

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

Question 14

Technician A says that any type of governor will work well when pulling heavy loads in off-road conditions without surging and causing driveline damage. Technician B says that an automotive governor is best suited to those operating conditions. Who is correct?

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

Question 15

Technicians A and B are making programmable parameter adjustments for the governor used by an engine to drive a PTO that is operating a hydraulic pump on a landscaping truck. Technician A says that the PTO throttle switch should be configured so that the engine governor that drives the PTO is a variable-speed governor. Technician B says that the engine should be set up to use an automotive-type governor when the PTO is operating. Who is correct?

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

Question 16

Technician A says that when starting a mechanically governed diesel engine, it is important to push the accelerator pedal to the floor once and then release it. Technician B says the injection pump will automatically go to part throttle when cranking, and so nothing needs to be done. Who is correct?

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

Question 17

Which one of the following would likely result if the line that connects mechanical air-fuel ratio control device to the turbocharger compressor outlet were broken?

A)Heavy black smoke during acceleration.
B)Poor fuel economy
C)Excessive engine speed.
D)Low power.

Question 18

While advising a customer about the consequences of increasing maximum engine rpm with an after market software program that alters the engine calibration and increases power output. Technician A says that the engine will produce more smoke. Technician B says the problem with emissions can be corrected by adjusting the air-fuel ratio control. Who is correct?

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

Question 19

Technician A says that the units on a scanner for a fuel pressure regulator energized by a PWM signal will be reported in volts and amps of electrical current. Technician B says that the units for a PWM signal may be reported as a percentage or in milliseconds Who is correct?

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

Question 20

Controlling an output device by using feedback from a single sensor is referred to as _________.

A)model predictive control (MPC)
B)proportional-integral-derivative (PID) control
C)closed-loop feedback
D)open-loop feedback

Question 21

Without the governors' ability to regulate fuel delivery for varying speed and load conditions, engine operation would at best be erratic and at worst result in:

A)rapid engine destruction"
B)poor fuel economy"
C)low emissions
D)injection pump failure"

Question 22

Technician A says that comprehending governor terms and principles is helpful to technicians when they analyze engine performance or emission-related problems. Technician B says that understanding governor operating principles will help build effective diagnostic and service skills. Who is right?

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

Question 23

On mechanical or electronically controlled high-pressure injection systems, very small changes in injection quantity produce very large changes in:

A)vehicle speed"
B)exhaust emissions"
C)engine speed
D)engine temperature"

Question 24

If only throttle linkage were connected in a way that directly controls fuel delivery, such as a control rack inside a high-pressure pump, the slightest movements of the throttle pedal would produce excessively large changes in:

A)vehicle speed"
B)exhaust emissions"
C)engine speed
D)engine temperature"

Question 25

In a mechanical injection pump, which section of the fuel injection pump is connected to the governor mechanism by the control rack?

A)High-pressure"
B)Low-pressure"
C)Lift pump
D)Pumping plungers"

Question 26

What is an engine's minimum operational speed?

A)Part-throttle"
B)Max fuel"
C)Idle
D)Mid-throttle"

Question 27

Limiting maximum engine speed and acceleration rate is also critical to:

A)engine temperature"
B)engine serviceability"
C)cabin temperature
D)emission control"

Question 28

Exceeding the rated speed of an engine will produce smoke emissions from incompletely burned fuel, because the time available for combustion events becomes

A)too short at high speeds"
B)too short at low speeds"
C)too long at high speeds
D)too long at slow speeds"

Question 29

Two technicians are discussing electronic diesel engine governors. Technician A says that programmable governor features fall into three basic categories: factory specified, customer specified, and dealer specified. Technician B says that almost any measurable variable affecting either engine or vehicle operation can be adjusted through programmable software. Who is right?

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

Question 30

Identify the typical programmable range in a governor for maximum cruise control speed.

A)25-50 mph"
B)50-125 mph"
C)30-102 mph
D)75-102 mph"

Question 31

Technician A says that horsepower (kilowatts), maximum torque output, and torque rise are adjustable without factory authorization. Technician B says that chassis manufacturer-specific parameters include calibrations for the tachometer and integration of chassis controllers to the onboard vehicle networks. Who is right?

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

Question 32

Partial-authority systems range from electronically controlling just cruise control functions to electronically governing all fuel metering and injection timing control by using:

A)mechanical unit injectors (MUI)"
B)electronic high-pressure injection system."
C)mechanical high-pressure injection system.
D)electronic u injectors (EUI)"

Question 33

What is more commonly referred to as electronic engine management in a diesel engine?

A)Electronic fuel injection"
B)LAN (Local Area Network)"
C)Partial-authority governing
D)Full-authority governing"

Question 34

Which of the following is another name for the automotive governor?

A)Isochronous governor"
B)Variable speed (VS)"
C)Limiting speed (LS)
D)Combination governors"

Question 35

Which type of governor requires the operator to adjust engine speed when the load that is applied to an engine changes?

A)Variable speed."
B)Limiting speed (LS)."
C)Hydraulic.
D)Servo."

Question 36

Technician A says that any type of governor will work well when pulling heavy loads in off-road conditions without surging and causing driveline damage. Technician B says that an automotive governor is best suited to those operating conditions. Who is correct?

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

Question 37

Technician A says that smoke, low power, hunting, engine stalling, poor acceleration, and excessive engine speed are some of the problems that indicate a governor may require evaluation. Technician B says that wire ties sealed with lead tags cover critical governor adjustments to prevent tampering, and imprint on the lead seal identifies the manufacturer or repair shop. Who is right?

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

Question 38

Two technicians are describing mechanical governor service. Technician A says that governor mechanisms are designed for wear and deterioration to increase engine speed and torque, not decrease it. Technician B says that air-fuel ratio devices are pressure tested to check for diaphragm leaks. Who is right?

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

Question 39

Air-fuel ratio devices have two adjustments, one adjustment is for controlling the initial starting point where:

A)maximum fuel limiting begins"
B)minimum fuel limiting begins"
C)minimum boost pressure takes place
D)maximum boost pressure takes place"

Question 40

Maximum engine speed is adjusted by increasing or decreasing the:

A)tension of governor high speed spring"
B)tension of governor flyweights"
C)internal adjustment screw
D)external adjustment screw"

Question 41

On mechanical governors with centrifugal flyweights, what can become weak because of age and heat and fatigue from constant compression and release cycling?

A)Screw stops"
B)Governor springs"
C)Governor weights
D)Plungers"

Question 42

Two technicians are describing a low power concern on a mechanical fuel injection pump. Technician A says that you should check the linkage with the accelerator pedal pressed to the floor to see if it reaches full throttle. Technician B says that weak governor spring can cause this concern. Who is right?

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

Question 43

Two technicians are testing maximum engine speed for a mechanical governor. Technician A says that you check the emission decal on the engine or the engine's service literature to find its high-idle speed or rated rpm. Technician B says that the engine should typically reach 10-20% above rated rpm speed with no-load acceleration. Who is right?

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

Question 44

Engine protection is a critical governor programmable setting. Faults that could potentially cause engine damage will cause the governor to do all of these, EXCEPT one. Which one is that?

A)Derate power"
B)Increase power"
C)Shut the engine down
D)Warn driver by using an instrument cluster warning lamp"

Question 45

Which of the following is NOT a major division of electronic governor control systems?

A)Sensing"
B)Processing"
C)Output or actuation
D)Diagnostics"

Question 46

What function of electronic governor control system refers to the control system element that collects sensor data and determines outputs based on a set of instructions or program software?

A)Sensing"
B)Processing"
C)Output
D)Diagnostics"

Question 47

Which of the following is NOT an electrical signal commonly used as either inputs and/or outputs in electronic engine control applications?

A)Analog"
B)Monolog"
C)Digital
D)PWM (pulse-width modulation)"

Question 48

Which of the following is an example of a component where analog data can be collected?

A)Hall-effect switch"
B)On-off switch"
C)Throttle-position sensor
D)Engine speed sensor"

Question 49

Which of the following is an electrical signal that varies in on and off time?

A)Analog"
B)Monolog"
C)Digital
D)PWM (pulse-width modulation)"

Question 50

What starts and stops a processing cycle to keep processing functions synchronized inside an ECM?

A)Microprocessor"
B)Clock"
C)Microcontrollers
D)A-D converter"

Question 51

Which of the following is a temporary storage place for information that needs to be quickly accessed?

A)Read-Only Memory (ROM)"
B)Random-Access Memory (RAM)"
C)Programmable Read-Only Memory (PROM)
D)Electrically Erasable Programmable Read-Only Memory (EEPROM)"

Question 52

Technician A says that the units on a scanner for a fuel pressure regulator energized by a PWM signal will be reported in volts and amps of electrical current. Technician B says that the units for a PWM signal may be reported as a percentage or in milliseconds Who is correct?

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

Question 53

Technician A says that the ECM will compare sensor data with an expected or commanded value provided by a calibration lookup table and ask a series of "if" questions. Technician B says if the lookup-table value matches the sensed measurement, then the ECM changes the electrical signal supplied to the actuator. Who is right?

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

Question 54

What type of control is also used to operate devices where the relationship between input and the output state can be easily modeled by a mathematical formula?

A)Closed-loop"
B)Open loop"
C)Partial
D)Absolute"

Question 55

Technician A says that PID control involves using control loops that use fixed lookup tables to continually adjust engine actuator output. Technician B says that when the lookup table is uploaded to an ECM, it is used to help solve mathematical problems such as how much fuel the ECM commands for injection. Who is right?

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

Question 56

What is the most commonly used engine calibration and control strategy in today's ECMs?

A)Model Predictive Engine Control (MPC)"
B)Proportional-Integral-Derivative (PID)"
C)Supplemental Integral Derivative (SID)
D)Partial-Authority Engine Control (PAEC)"

Question 57

The model predictive engine control (MPC) calibration strategy makes a decision about a particular future control step or sequence based on:

A)look-up tables"
B)mathematical equations"
C)a future data sample
D)current data sample"

Question 58

A manufacturer may have used ____ models to predict optimal actuator output states.

A)5"
B)10"
C)15
D)20"

Question 59

What is the most commonly used engine calibration and control strategy used by today's ECMs?

A)Proportional-Integral-Derivative (PID)"
B)Supplemental Integral Derivative (SID)"
C)Model Predictive Engine Control (MPC)
D)Partial-Authority Engine Control (PAEC)"

Question 60

Which control system has faster microprocessors that have larger memory storage capacity, made possible by the desktop computer?

A)Model Predictive Engine Control (MPC)"
B)Proportional-Integral-Derivative (PID)"
C)Supplemental Integral Derivative (SID)
D)Partial-Authority Engine Control (PAEC)"