ENGINE PERFORMANCE STATE PRACTICE TEST
QUESTIONS & VERIFIED ANSWERS
On an OBD II system, a loose gas cap will cause?
The malfunction indicator lamp (MIL) to turn on
poor fuel mileage
a hard start condition
engine hesitation - Answers - The malfunction indicator lamp (MIL) to turn on
You have verified a slow cranking complaint. Which of the following should you do next?
determine if the solenoid is making contact when the ignition key is turned to the start
position
determine the condition of the battery
check the voltage drop in the starter circuit
perform a starter draw test - Answers - determine the condition of the battery
The scope pattern below was obtained on the 30KV scale. What is the available
voltage?
7 kv
13 kv
4 kv
29 kv - Answers - 29 kv
If the ignition timing will not advance past base timing the problem may be:
crank sensor broken
fuel trim out of range
cam timing incorrect
vehicle in limp mode - Answers - vehicle in limp mode
A weak ignition coil would most likely appear in which section of the scope pattern?
A
B
C
None of the above - Answers - B
The powertrain Control Module (PCM) uses the Throttle position Sensor (TPS) signal
information to adjust all of the following except:
, Air/fuel ratio
Ignition timing
Fuel pressure
EGR flow - Answers - Fuel pressure
Which of the following could result in an infrared analyzer giving a higher than actual HC
reading?
failing to purge the sample hose before testing
failing to insert the sample hose into the tail pipe more than four inches
a kinked or collapsed sampling hose
sampling hose inserted too far into the tail pipe - Answers - failing to purge the sample
hose before testing
Most vehicles are designed to go into a closed loop operation when:
-the engine temperature reaches a calibrated level
-the TPS is at part or closed throttle
-the exhaust gas oxygen sensor voltage is switching regularly between low and high
voltage signals
-all of the above - Answers - All of the above
Increased EGR flow, at constant throttle, will result in:
increased fuel injector pulse width
decreased injector pulse width
no change in injector pulse width
none of the above - Answers - increased fuel injector pulse width
Electronic fuel injection is best described by which of the following?
Electromagnetism raises the plungers in the injectors off their seats and spring pressure
returns the plungers to their seats
Injector pulse width is controlled by electricity but the injectors are physically activated
by the camshaft
A crankshaft sensor electronically signals the controller when the proper amount of fuel
has been injected
all of the above - Answers - Electromagnetism raises the plungers in the injectors off
their seats and spring pressure returns the plungers to their seats
Which of the following could cause engine detonation?
carbon build up on pistions
EGR stuck closed
Both A and B
neither A nor B - Answers - Both A and B
QUESTIONS & VERIFIED ANSWERS
On an OBD II system, a loose gas cap will cause?
The malfunction indicator lamp (MIL) to turn on
poor fuel mileage
a hard start condition
engine hesitation - Answers - The malfunction indicator lamp (MIL) to turn on
You have verified a slow cranking complaint. Which of the following should you do next?
determine if the solenoid is making contact when the ignition key is turned to the start
position
determine the condition of the battery
check the voltage drop in the starter circuit
perform a starter draw test - Answers - determine the condition of the battery
The scope pattern below was obtained on the 30KV scale. What is the available
voltage?
7 kv
13 kv
4 kv
29 kv - Answers - 29 kv
If the ignition timing will not advance past base timing the problem may be:
crank sensor broken
fuel trim out of range
cam timing incorrect
vehicle in limp mode - Answers - vehicle in limp mode
A weak ignition coil would most likely appear in which section of the scope pattern?
A
B
C
None of the above - Answers - B
The powertrain Control Module (PCM) uses the Throttle position Sensor (TPS) signal
information to adjust all of the following except:
, Air/fuel ratio
Ignition timing
Fuel pressure
EGR flow - Answers - Fuel pressure
Which of the following could result in an infrared analyzer giving a higher than actual HC
reading?
failing to purge the sample hose before testing
failing to insert the sample hose into the tail pipe more than four inches
a kinked or collapsed sampling hose
sampling hose inserted too far into the tail pipe - Answers - failing to purge the sample
hose before testing
Most vehicles are designed to go into a closed loop operation when:
-the engine temperature reaches a calibrated level
-the TPS is at part or closed throttle
-the exhaust gas oxygen sensor voltage is switching regularly between low and high
voltage signals
-all of the above - Answers - All of the above
Increased EGR flow, at constant throttle, will result in:
increased fuel injector pulse width
decreased injector pulse width
no change in injector pulse width
none of the above - Answers - increased fuel injector pulse width
Electronic fuel injection is best described by which of the following?
Electromagnetism raises the plungers in the injectors off their seats and spring pressure
returns the plungers to their seats
Injector pulse width is controlled by electricity but the injectors are physically activated
by the camshaft
A crankshaft sensor electronically signals the controller when the proper amount of fuel
has been injected
all of the above - Answers - Electromagnetism raises the plungers in the injectors off
their seats and spring pressure returns the plungers to their seats
Which of the following could cause engine detonation?
carbon build up on pistions
EGR stuck closed
Both A and B
neither A nor B - Answers - Both A and B
