Engine Performance Exam Questions
& Answers (Grade A+).
1. A technician is measuring the resistance across a coolant
temperature sensor (CTS) with a DMM. Using the chart, which of
these readings would represent a good sensor at 27°C (80.6 F)?
A. 3,000 Ohms
B. 2,800 Ohms
C. 2,500 Ohms
D. 2,000 Ohms -
correct answer ✅C. 2,500 Ohms
2. Excessive CO emissions are caused by:
A. fouled spark plugs.
B. rich air/fuel mixtures.
C. high combustion chamber temperatures.
D. carbon build-up in the combustion chambers. -
correct answer ✅B. rich air/fuel mixtures.
3. A vehicle with a DIS ignition has a misfire on cylinders 2 and 5.
The misfire remains on cylinders 2 and 5 when the 2/5 coil is
swapped with the 6/3 coil. Which of these could be the cause?
A. The fuel pressure is low.
B. The head gasket has failed.
,Engine Performance Exam Questions
& Answers (Grade A+).
C. The 6/3 coil is faulty.
D. The ignition module is faulty. -
correct answer ✅D. The ignition module is faulty.
4. During an engine compression test, the technician observes a
low pressure reading on cylinder #1. All other cylinders are normal.
This could be caused by:
A. A burned exhaust valve.
B. A worn camshaft exhaust lobe.
C. Incorrect valve timing.
D. A worn valve stem seal. -
correct answer ✅A. A burned exhaust valve.
5. A constant spark knock is heard while the vehicle is at cruising
speed. Technician A says that clogged EGR passages could be the
cause. Technician B says that a stuck-open cooling system
thermostat could be the cause. Who is right?
A. A only
B. B only
C. Both A and B
,Engine Performance Exam Questions
& Answers (Grade A+).
D. Neither A nor B -
correct answer ✅A. A only
7. Ignition "dwell" refers to the:
A. Time that current flows in the primary coil.
B. Total current value in the primary coil.
C. Peak primary voltage.
D. Secondary firing voltage level. -
correct answer ✅A. Time that current flows in the primary coil.
6. An engine cranks but will not start. While cranking there is no
spark, but the fuel pump is running and the injectors make an
audible clicking sound. This could be caused by a failed:
A. Ignition module.
B. Crank sensor.
C. Oxygen sensor.
D. Throttle position sensor. -
correct answer ✅A. Ignition module.
8. The following question contains the word EXCEPT. Read the
question carefully and look for the choice that could NOT cause the
, Engine Performance Exam Questions
& Answers (Grade A+).
described situation. All of the following procedures can be used to
relieve fuel pressure EXCEPT to:
A. Disconnect the ignition module and crank the engine for 3
seconds.
B. Disconnect the fuel pump and crank the engine for 3 seconds.
C. Remove the fuel pump fuse and crank the engine for 3 seconds.
D. Remove the fuel pump relay and crank the engine for 3 seconds.
-
correct answer ✅A. Disconnect the ignition module and crank the
engine for 3 seconds.
9. A technician is performing a fuel pressure test on a fuel injected
engine. When the ignition switch is turned on, the fuel pressure
jumps to specification, then immediately drops to zero psi. This
could be caused by:
A. A stuck closed regulator.
B. A leaking fuel pump check valve.
C. A clogged fuel filter.
D. An intermittent fuel pump ground. -
correct answer ✅B. A leaking fuel pump check valve.
10. The lab scope pattern shown indicates which condition?
& Answers (Grade A+).
1. A technician is measuring the resistance across a coolant
temperature sensor (CTS) with a DMM. Using the chart, which of
these readings would represent a good sensor at 27°C (80.6 F)?
A. 3,000 Ohms
B. 2,800 Ohms
C. 2,500 Ohms
D. 2,000 Ohms -
correct answer ✅C. 2,500 Ohms
2. Excessive CO emissions are caused by:
A. fouled spark plugs.
B. rich air/fuel mixtures.
C. high combustion chamber temperatures.
D. carbon build-up in the combustion chambers. -
correct answer ✅B. rich air/fuel mixtures.
3. A vehicle with a DIS ignition has a misfire on cylinders 2 and 5.
The misfire remains on cylinders 2 and 5 when the 2/5 coil is
swapped with the 6/3 coil. Which of these could be the cause?
A. The fuel pressure is low.
B. The head gasket has failed.
,Engine Performance Exam Questions
& Answers (Grade A+).
C. The 6/3 coil is faulty.
D. The ignition module is faulty. -
correct answer ✅D. The ignition module is faulty.
4. During an engine compression test, the technician observes a
low pressure reading on cylinder #1. All other cylinders are normal.
This could be caused by:
A. A burned exhaust valve.
B. A worn camshaft exhaust lobe.
C. Incorrect valve timing.
D. A worn valve stem seal. -
correct answer ✅A. A burned exhaust valve.
5. A constant spark knock is heard while the vehicle is at cruising
speed. Technician A says that clogged EGR passages could be the
cause. Technician B says that a stuck-open cooling system
thermostat could be the cause. Who is right?
A. A only
B. B only
C. Both A and B
,Engine Performance Exam Questions
& Answers (Grade A+).
D. Neither A nor B -
correct answer ✅A. A only
7. Ignition "dwell" refers to the:
A. Time that current flows in the primary coil.
B. Total current value in the primary coil.
C. Peak primary voltage.
D. Secondary firing voltage level. -
correct answer ✅A. Time that current flows in the primary coil.
6. An engine cranks but will not start. While cranking there is no
spark, but the fuel pump is running and the injectors make an
audible clicking sound. This could be caused by a failed:
A. Ignition module.
B. Crank sensor.
C. Oxygen sensor.
D. Throttle position sensor. -
correct answer ✅A. Ignition module.
8. The following question contains the word EXCEPT. Read the
question carefully and look for the choice that could NOT cause the
, Engine Performance Exam Questions
& Answers (Grade A+).
described situation. All of the following procedures can be used to
relieve fuel pressure EXCEPT to:
A. Disconnect the ignition module and crank the engine for 3
seconds.
B. Disconnect the fuel pump and crank the engine for 3 seconds.
C. Remove the fuel pump fuse and crank the engine for 3 seconds.
D. Remove the fuel pump relay and crank the engine for 3 seconds.
-
correct answer ✅A. Disconnect the ignition module and crank the
engine for 3 seconds.
9. A technician is performing a fuel pressure test on a fuel injected
engine. When the ignition switch is turned on, the fuel pressure
jumps to specification, then immediately drops to zero psi. This
could be caused by:
A. A stuck closed regulator.
B. A leaking fuel pump check valve.
C. A clogged fuel filter.
D. An intermittent fuel pump ground. -
correct answer ✅B. A leaking fuel pump check valve.
10. The lab scope pattern shown indicates which condition?
