|
|||||||
|
|
|
|||||
|
|
|||||||
|
|||||||
|
|
|
|||||
|
|
|||||||
Use the information from
this Unit and chapters 14 and 15, Auto Fundamentals,
Stockel, Stockel and Johanson, to answer the following questions.
You may also need to refer
back to the OBD2 link. Use information from the library or
the Internet when necessary.
1. The combustion chamber in modern cylinder heads is
designed to reduce
the amount of _______
in the exhaust.
a. CO
b. NOx
c. HC
d. O2
2. All of the following statements about lower engine
compression ratios are
true EXCEPT
a. lower compression ratios allow use of lower octane fuel
b. NOx formation is greater with low compression ratios
c. lower compression allows the engine to operate on unleaded fuel
d. detonation is less likely to occur with lower compression ratios
3. Dieseling is caused by hot spots in the
a. block
b. intake manifold
c. combustion chamber
d. exhaust manifold
4. Technician A says that carburetor icing is reduced
by the use of a thermostatic
air cleaner. Technician
B says that carburetor icing is reduced by the use of
early fuel evaporative
systems. Who is right?
a. A only
b. B only
c. both A and B
d. neither A nor B
5. Lowering the combustion flame termperature reduces the formation of
a. HC
b. NOx
c. CO
d. O2
6. Technician A says that the EGR valve admits exhaust
gases to the intake
manifold at all times.
Technician B says that the PCV valve admits crankcase
fumes into the intake
manifold at all times. Who is right?
a. A only
b. B only
c. both A and B
d. neither A nor B
7. The air injection (thermactor air pump) system forces air into the
a. intake manifold near the intake valve
b. exhaust manifold near the exhaust valve
c. catalytic convertor
d. all of the above depending on the system
8. What unit provides air for the air injection system?
a. fan
b. air pump
c. air cleaner snorkel ram pressure
d. intake system back pressure
9. All of the following statements about air switching
valves are true
EXCEPT for
a. the switching valve can channel pump air
to the intake manifold, exhaust manifold
or the catalytic convertor
b. the switching valve can be used to perform
the normal diverter valve functions
c. some switching valves channel pump air
between the exhaust port area and the
catalytic convertor
d. the switching valve reduces the efficiency
of the catalytic convertor
10. Technician A says that the thermostatically controlled
air cleaner admits
cool air to the engine
during engine warmup. Technician B says that the
thermostatically controlled
air cleaner allows a leaner air/fuel mixture
during the warmup period.
Who is right?
a. A only
b. B only
c. both A and B
d. neither A nor B
11. The pellet-type convertor catalyst bed is being replaced
because it creates
more ________ than the monolith type.
a. heat
b. back pressure
c. noise
d. vibration
12. A reducing catalyst can lower _________ emissions.
a. HC
b. NOx
c. CO
d. all of the above
13. The operation of the three-way air-injected catalytic convertor
requires all
of the following EXCEPT
a. a rhodium catalyst
b. an air injection pump
c. an oxidizing catalyst
d. a vacuum operated EGR valve
14. Many vehicles with emission controls reduce ignition timing
advance by placing
a restrictor on the ___________
advance mechanism.
a. vacuum
b. centrifugal
c. electronic
d. none of the above
15. To prevent carnkcase fumes from escaping to the atmosphere,
all modern
engines are equipped
with a(n) ________ system.
a. EGR
b. PCV
c. diverter valve
d. thermostatic air cleaner
16. Technician A says that crankcase gases are allowed to flow
freely into the
intake manifold during
engine idle. Technician B says that the vapour
canister is filled with
fiberglass. Who is right?
a. A only
b. B only
c. both A and B
d. neither A nor B
17. In the closed (ECS) fuel system, liquid fuel must NOT enter the
a. fuel lines
b. fuel return lines
c. carbon canister
d. all of the above
18. The pressure-vacuum cap used on a sealed fuel tank has
a
___________ valve.
a. pressure relief
b. vacuum relief
c. rollover
d. both A and B
19. The conventional convertor changes HC and CO into
a. NOx
b. NOx and H2O
c. HC and CO2
d. CO2 and H2O
20. The purpose of the PCV system is to
a. remove blowby gases from the crankcase
b. regulate the flow of fresh air to the intake
c. increase fuel economy
d. provide fresh air to the convertor
21. Technician A says leaner air/fuel ratios reduce hydrocarbons
but
increase NOx. Technician
B says that additional pollution controls are
required to reduce NOx.
Who is right?
a. A only
b. B only
c. both A and B
d. neither A nor B
22. As combustion efficiency increases to reduce HC and CO
emissions,
what happens to NOx?
a. NOx is eliminated
b. NOx increases
c. NOx decreases
d. there is no effect on NOx
23. A four-gas analyzer is being used on an engine. Technician
A says that
CO and HC can be tested.
Technician B says that CO2 and O2 can be
tested. Who is
right?
a. A only
b. B only
c. both A and B
d. neither A nor B
24. OBD2 requires manufacturers to use
a. a standard DLC connector
b. standard codes
c. two oxygen sensors
d. all of the above
25. Evaporative emission leaks from the fuel system are monitored
in
OBD2 by using a
a. second O2 sensor
b. pressure sensor in the vapour recovery system
c. HC sensor in the engine compartment
d. fan assembly in the fuel tank