Engine Performance Final Exam
Questions & Answers
Technician A says a defective PCV valve rough idle operation.
Technician B says the PCV system depends upon a properly sealed
engine to perform correctly. Who is correct? -
correct answer ✅Both A and B
A loss of residual fuel pressure immediately after engine shutdown
could cause ______. -
correct answer ✅Hard starting
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 A nor b
The typical amount of secondary coil voltage required to jump the
spark plug gap is _____ volts. -
correct answer ✅10,000
In closed loop, the PCM adjusts the pulse width according to inputs
from a variety of sensors, but primarily the ______. (TP, ECT, IAT,
O2S) -
correct answer ✅O2s
, Engine Performance Final Exam
Questions & Answers
The typical amount of secondary coil voltage required to jump the
spark plug gap is _____ volts. -
correct answer ✅10,000
The longest injector pulse width occurs during ______. -
correct answer ✅cold starting
(T/F) GDI systems allow engines to run at very lean air/fuel ratios
and eliminate the need for EGR systems. -
correct answer ✅False
An air/fuel ratio sensor is different from an oxygen sensor in that
______. The signal output is a varying current. As the mixture
becomes leaner, its output signal increases. The output responds to
minor changes in air/fuel mixture. -
correct answer ✅All are correct
Technician A says engine vacuum is normally measured in inches of
mercury (in. Hg). Technician B says a pressure gauge that is labeled
psig will read 14.7 psi at sea level. Who is correct? -
correct answer ✅A only
Questions & Answers
Technician A says a defective PCV valve rough idle operation.
Technician B says the PCV system depends upon a properly sealed
engine to perform correctly. Who is correct? -
correct answer ✅Both A and B
A loss of residual fuel pressure immediately after engine shutdown
could cause ______. -
correct answer ✅Hard starting
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 A nor b
The typical amount of secondary coil voltage required to jump the
spark plug gap is _____ volts. -
correct answer ✅10,000
In closed loop, the PCM adjusts the pulse width according to inputs
from a variety of sensors, but primarily the ______. (TP, ECT, IAT,
O2S) -
correct answer ✅O2s
, Engine Performance Final Exam
Questions & Answers
The typical amount of secondary coil voltage required to jump the
spark plug gap is _____ volts. -
correct answer ✅10,000
The longest injector pulse width occurs during ______. -
correct answer ✅cold starting
(T/F) GDI systems allow engines to run at very lean air/fuel ratios
and eliminate the need for EGR systems. -
correct answer ✅False
An air/fuel ratio sensor is different from an oxygen sensor in that
______. The signal output is a varying current. As the mixture
becomes leaner, its output signal increases. The output responds to
minor changes in air/fuel mixture. -
correct answer ✅All are correct
Technician A says engine vacuum is normally measured in inches of
mercury (in. Hg). Technician B says a pressure gauge that is labeled
psig will read 14.7 psi at sea level. Who is correct? -
correct answer ✅A only
