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1. Technician A says that fuel injection is used to obtain
precise air/fuel ratios. Technician B says that fuel
injection systems are designed only to produce greater
horsepower. Who is right?
a. A only
b. B only
c. both A and B
d. neither A nor B
2. All of the following are true about pressure regulators
except
a. some fuel injection systems have
no regulator
b. some regulators have a vacuum
connection
c. some regulators release pressure
into a tank
return hose
d. all regulators have an internal
spring
3. Fuel system pressure in a CIS system is controlled by a
a. mechanical air flow
sensor
b. mass air flow sensor
c. electric solenoid
d. electronic control
unit
4. Electronic fuel injection uses sensors to
a. measure engine temperature
b. control exhaust emissions
c. regulate air flow
d. monitor engine conditions
5. All of the following are true about intake manifold vacuum
except:
a. high load cause
low vacuum
b. vacuum increases
as load increases
c. low load causes
high vacuum
d. vacuum is inversely
proportional to load
6. Technician A says that stoichiometric air/fuel ratio is
always maintained by the injection system. Technician
B
says that stoiciometric ratios are maintained unless
the
engine is cold or under load. Who is right?
a. A only
b. B only
c. both A and B
d. neither A nor
B
7. Which system has a sensing element that must be kept heated
to 75 deg. C (167 deg. F) above the intake air temperature?
a. VAF sensor
b. MAP sensor
c. MAF sensor
d. IAC
8. The fuel pressure regulator
a. controls
the fuel pressure entering the pump
b. provides
fuel to the fuel charging unit
c. maintains
the proper fuel pressure to the
injectors
d. forces
fuel into the injectors
9. Correct stoichiometric air/fuel ratio is
a. 12.5:1
b. 14.7:1
c. 16.6:1
d. 18.2:1
10. An injector clicks during operation. Technician A says to
replace the injector. Technician B says it is
operting
properly. Who is right?
a. A only
b. B only
c. Both A
and B
d. Neither
A nor B
11. Injectors in the continuous fuel injection system are opened
by
a. spring
pressure
b. fuel pressure
c. air pressure
d. solenoids
12. Which of the following is not part of the fuel distribution
system?
a. fuel tank
b. catalytic
convertor
c. fuel pump
d. fuel filter
13. An air/fuel ratio of 13.1:1
a. creates
a rich mixture
b. increases
NOx formation
c. creates
a lean mixture
d. is maintained
for most engine conditions
14. TBI stands for
a. throttle
block-learn injection
b. timed
body injection
c. throttle
body injection
d. throttle
by-pass injection
15. The 02 sensor produces a voltage through
a. heat
b. thermistor
action
c. pressure
d. chemical
reaction
16. Which of the following is a type of fuel injection?
a. throttle
body
b. sequential
c. continuous
d. all of
the above
17. In a CIS system, air fuel ratio is controlled by
a. pressure
b. manifold
vacuum
c. engine
speed
d. airflow
sensor
18. EFI fuel injectors open through the use of a
a. plunger
b. diapraghm
c. solenoid
d. all of
the above
19. Technician A says that multiport injection systems have one
injector per cylinder. Technician B says that
throttle body
injection systems have one or two
injectors. Who is right?
a. A only
b. B only
c. Both A
and B
d. Neither
A nor B
20. Technician A says that there are high and low pressure
injection systems. Technician B says that there
are
continuous and timed injection systems.
Who is right?
a. A only
b. B only
c. both A
and B
d. neither
A nor B
21. In a mass airflow sensor the wire is heated by
a. an electric
current
b. heated
airflow
c. exhaust
gases
d. engine
heat
22. The fuel injectors on a CFI system are located in the
a. cylinder
head in front of the intake valves
b. fuel charging
assembly
c. combustion
chamber above the pistons
d. intake
manifold in front of the intake valves
23. An air/fuel ratio of 15.7:1
a. creates
a rich mixture
b. is maintained
for most engine operations
c. increases
hydrocarbon formation
d. creates
a lean mixture
24. The length of time an injector is energized is called
a. open loop
b. pulse
width
c. dwell
time
d. closed
loop
25. Technician A says that on fuel injected vehicles, the fuel
pressure is controlled by the computer. Technician
B says
that injector pulse width is the amount of time
the injector
is turned on. Who is right?
a.
A only
b.
B only
c.
Both A and B
d.
Neither A nor B
KEY - QUIZ 5