Engine Performance Final Exam
Questions & Answers (Grade A+)
Higher compression ratios tend to speed up combustion. -
correct answer ✅true
The MIL light should illuminate when the ignition switch is turned
to the run position [engine not running] and go out within a few
seconds after the engine is started. -
correct answer ✅true
Engine vacuum is being discussed. Technician A says that when the
engine is operating under light loads, engine vacuum is low.
Technician B says that engine vacuum is high when the engine is
operated under heavy loads. Who is correct? -
correct answer ✅neither
Which of the following is NOT an advantage of an electronic spark
control system?
a.
It compensates for changes in engine (and sometimes outside air)
temperature
b.
It allows lower compression ratio engines to be as efficient as
higher compression ratio engines
,Engine Performance Final Exam
Questions & Answers (Grade A+)
c.
It makes changes many times faster than older (mechanical)
systems
d.
It has a feedback mechanism which allows it to constantly
compensate for changing conditions -
correct answer ✅b
The first decision the computer makes in determining the best
operating strategy is to determine the _____. -
correct answer ✅engine operating mode
Catalytic converter monitors are being discussed. Technician A says
that if the converter is working, the downstream signal frequency
should mirror the upstream sensor. Technician B says that the
downstream sensor should provide a low-frequency voltage signal.
Who is correct? -
correct answer ✅b only
Oxygen sensor monitors are being discussed. Technician A says the
system monitors the sensor response time as the system cycles
lean-rich-lean. Technician B says that at certain times the monitor
varies the fuel delivery and checks for heated oxygen sensor
, Engine Performance Final Exam
Questions & Answers (Grade A+)
response. Who is correct? -
correct answer ✅both a and b
EGR monitors are being discussed. Technician A says some EGR
system monitors EGR flow by measuring the difference in pressure
as the EGR gas flows through an orifice (restriction). Technician B
says some EGR monitors measure the temperature of the EGR
outlet to determine whether there is gas flowing through the EGR
valve. Who is correct? -
correct answer ✅both a and b
Which of the following sensors is NOT used by the computerized
ignition system to control ignition timing? -
correct answer ✅oxygen sensor
OBD II technology is being discussed. Technician A says the OBD II
system has the ability to store a freeze frame (snapshot) of the
operating conditions that existed when the fault occurred.
Technician B says vehicle identification must be transmitted
automatically to the scan tool. Who is correct? -
correct answer ✅both a and b
Questions & Answers (Grade A+)
Higher compression ratios tend to speed up combustion. -
correct answer ✅true
The MIL light should illuminate when the ignition switch is turned
to the run position [engine not running] and go out within a few
seconds after the engine is started. -
correct answer ✅true
Engine vacuum is being discussed. Technician A says that when the
engine is operating under light loads, engine vacuum is low.
Technician B says that engine vacuum is high when the engine is
operated under heavy loads. Who is correct? -
correct answer ✅neither
Which of the following is NOT an advantage of an electronic spark
control system?
a.
It compensates for changes in engine (and sometimes outside air)
temperature
b.
It allows lower compression ratio engines to be as efficient as
higher compression ratio engines
,Engine Performance Final Exam
Questions & Answers (Grade A+)
c.
It makes changes many times faster than older (mechanical)
systems
d.
It has a feedback mechanism which allows it to constantly
compensate for changing conditions -
correct answer ✅b
The first decision the computer makes in determining the best
operating strategy is to determine the _____. -
correct answer ✅engine operating mode
Catalytic converter monitors are being discussed. Technician A says
that if the converter is working, the downstream signal frequency
should mirror the upstream sensor. Technician B says that the
downstream sensor should provide a low-frequency voltage signal.
Who is correct? -
correct answer ✅b only
Oxygen sensor monitors are being discussed. Technician A says the
system monitors the sensor response time as the system cycles
lean-rich-lean. Technician B says that at certain times the monitor
varies the fuel delivery and checks for heated oxygen sensor
, Engine Performance Final Exam
Questions & Answers (Grade A+)
response. Who is correct? -
correct answer ✅both a and b
EGR monitors are being discussed. Technician A says some EGR
system monitors EGR flow by measuring the difference in pressure
as the EGR gas flows through an orifice (restriction). Technician B
says some EGR monitors measure the temperature of the EGR
outlet to determine whether there is gas flowing through the EGR
valve. Who is correct? -
correct answer ✅both a and b
Which of the following sensors is NOT used by the computerized
ignition system to control ignition timing? -
correct answer ✅oxygen sensor
OBD II technology is being discussed. Technician A says the OBD II
system has the ability to store a freeze frame (snapshot) of the
operating conditions that existed when the fault occurred.
Technician B says vehicle identification must be transmitted
automatically to the scan tool. Who is correct? -
correct answer ✅both a and b
