3.4 Exercises for Unit 3

1. What types of additives are used in gasoline to slow down ignition?

A. Antiping
B. Antiknock
C. Anticombustion
D. Antioxidants

2. Which property is NOT a property of gasoline?

A. Volatility
B. Antiknock quality
C. Cetane number
D. Octane rating

3. What term refers to the measurement of the ability of a fuel to resist knock or ping?

A. Air-fuel ratio
B. Cetane number
C. Volatility
D. Octane rating

4. An air-fuel mixture that is too lean will cause which condition?

A. Increased power
B. Increased fuel consumption
C. Poor engine performance
D. Decreased exhaust emissions

5. Which is NOT a condition of abnormal combustion?

A. Detonation
B. Dieseling
C. Pre-ignition
D. Spark ping

6. Which factor can cause dieseling in a gasoline engine?

A. Low octane fuel
B. Low heat range spark plugs
C. Incorrect timing
D. Hot exhaust valve

7. What device is used in the filler neck of a gasoline fuel tank to prevent the accidental use of leaded fuel?

A. Fuel valve
B. Restrictor
C. Vacuum valve
D. Fuel nozzle

8. What is the function of the baffles in a fuel tank?

A. To reinforce the bottom of the fuel tank
B. To reinforce the sides of the fuel tank
C. To prevent the fuel from sloshing and splashing
D. To prevent the escape of fuel and fuel vapors from the tank

9. Fuel filters are NOT made of which material?

A. Sintered brass
B. Ceramic
C. Treated paper
D. Metal screen

10. What is the function of the fuel pump?

A. To measure the amount of fuel that enters the carburetor or fuel injectors
B. To deliver the fuel from the tank to the engine under pressure
C. To pump fuel from the carburetor to the intake manifold
D. To pump fuel from the carburetor through the fuel filter into the manifold

11. Fuel line tubing is normally made of what material?

A. Single-wall steel
B. Double-wall steel
C. Single-wall copper
D. Double-wall copper

12. Which attribute is NOT an advantage of a gasoline injection system over a carburetor type system?

A. Improved atomization
B. Better fuel distribution
C. Richer fuel mixture
D. Lower emissions

13. In a gasoline indirect injection system, fuel is sprayed into what part?

A. Precombustion chamber
B. Cylinder
C. Combustion chamber
D. Intake manifold

14. Of the gasoline fuel injection systems, what system is the most precise and also the most complex?

A. Hydraulic-timed injection
B. Throttle body fuel injection
C. Timed fuel injection
D. Continuous fuel injection

15. In a mechanical-timed injection system, the throttle valve regulates engine speed and power output by regulating the _____.

A. intake pressure
B. manifold vacuum
C. exhaust pressure
D. metering pump vacuum

16. Which is NOT a subsystem of an electronic-timed fuel injection system?

A. Fuel delivery system
B. Air induction system
C. Computer control system
D. Fuel metering system

17. In an electronic fuel injection system, what sensor measures the amount of outside air entering the engine?

A. Air flow
B. Inlet air temperature
C. Manifold pressure
D. Oxygen

18. In an electronic fuel injection system, where does the fuel pressure regulator divert the excess fuel?

A. Back to the fuel tank
B. To the inlet side of the fuel filter
C. To the inlet side of the fuel pump
D. Back to the inlet side of the fuel line

19. What component of a throttle body injection system contains the fuel pressure regulator?

A. Throttle air horn
B. Throttle body housing
C. Throttle positioner
D. Throttle fuel mixture valve

20. In a multi port fuel injection system, what component supplies fuel to the injectors?

A. Fuel tube
B. Fuel rail
C. Siphon pipe
D. Pressure regulator

21. Of the following chemical compounds, which is the most dangerous emission?

A. Carbon dioxide
B. Carbon monoxide
C. Hydrocarbons
D. Oxides of nitrogen

22. Exhaust manifolds are made from what type of material?

A. Aluminum
B. Steel
C. Cast iron
D. Iron alloy

23. What device is used to reduce the acoustic pressure of exhaust gases and discharge the gases into the atmosphere?

A. Resonator
B. Catalytic converter
C. Muffler
D. Exhaust manifold

24. The catalytic converter changes carbon monoxide and hydrocarbons into carbon dioxide and _____.

A. hydrogen
B. oxygen
C. methane
D. water

25. What two materials that act as a catalyst can be found inside a catalytic converter?

A. Silver and bronze
B. Bronze and platinum
C. Silver and palladium
D. Platinum and palladium

26. In an air injection system, what device is used to prevent air from entering the exhaust system during deceleration?

A. Air distribution manifold
B. Air check valve
C. Air pump
D. Diverter valve

27. What device keeps exhaust gases from entering the air injection system?

A. Air check valve
B. Diverter valve
C. Air distribution manifold
D. Air pump

28. (True or False) The open type positive crankcase ventilation system has a sealed breather that is connected to the air filter by a hose.

A. True
B. False

29. To control the formation of oxides of nitrogen, the exhaust gas recirculation system recirculates a portion of the exhaust gases back through the _____.

A. intake manifold
B. exhaust manifold
C. muffler
D. catalytic converter

30. At idle, engine vacuum is blocked off so it cannot act on the EGR valve. This is

accomplished by a closed _____.

A. diverter valve
B. vacuum diaphragm
C. throttle plate
D. heat control valve

31. What valve prevents fuel from entering the fuel tank vent line in the event of a accident in which the vehicle turns over?

A. Purge
B. Fuel tank
C. Roll-over
D. Spillage

32. (True or False) The charcoal canister does NOT store fuel vapors when the engine is running.

A. True
B. False

33. What component connects the charcoal canister to the engine intake manifold and is used to clean out stored fuel vapors from the charcoal canister?

A. Purge line
B. Carburetor vent line
C. Fuel tank vent line
D. Liquid-vapor separator