Engine Repair Questions and Answers
Latest Version Graded A+
What is the most likely result of a clogged fuel injector?
A. High oil pressure
✔✔B. Engine misfire
C. Stuck throttle
D. Knocking noise from the transmission
What does a faulty mass airflow (MAF) sensor commonly cause?
A. Weak spark at idle
✔✔B. Incorrect air-fuel mixture
C. Poor belt alignment
D. Engine knocking from overheating
What component maintains correct ignition timing in modern engines?
A. Ignition coil
✔✔B. Engine control module (ECM)
C. Fuel rail
1
,D. Camshaft sensor
Which sensor monitors the position of the crankshaft?
✔✔A. Crankshaft position sensor
B. Oxygen sensor
C. Knock sensor
D. Oil pressure sensor
If an engine stalls shortly after starting, what is a likely cause?
✔✔A. Faulty idle air control valve
B. Clean spark plugs
C. Excessive fuel pressure
D. Cool radiator
A stuck open thermostat will likely cause:
✔✔A. Engine running below optimal temperature
B. Overheating
C. Engine knocking
2
,D. Fuel injector damage
What is the function of a PCV (positive crankcase ventilation) valve?
✔✔A. To vent combustion gases from the crankcase
B. To control fuel injection
C. To increase oil pressure
D. To regulate spark timing
Which reading on a compression test would suggest a healthy cylinder?
A. 50 psi
✔✔B. 160 psi
C. 30 psi
D. 90 psi
A spark plug with black, sooty deposits may indicate:
✔✔A. Rich fuel mixture
B. Lean mixture
C. Coolant leak
3
, D. Cracked head gasket
What is one purpose of a catalytic converter?
A. Increase engine power
✔✔B. Reduce harmful exhaust emissions
C. Store exhaust gases
D. Cool the exhaust system
A technician finds metal shavings in the engine oil. What is the likely cause?
✔✔A. Internal engine wear or damage
B. Faulty fuel pump
C. Rich air-fuel mixture
D. Vacuum leak
Why might an engine crank but not start?
A. Low oil level
B. Dirty cabin air filter
✔✔C. No spark or no fuel delivery
4
Latest Version Graded A+
What is the most likely result of a clogged fuel injector?
A. High oil pressure
✔✔B. Engine misfire
C. Stuck throttle
D. Knocking noise from the transmission
What does a faulty mass airflow (MAF) sensor commonly cause?
A. Weak spark at idle
✔✔B. Incorrect air-fuel mixture
C. Poor belt alignment
D. Engine knocking from overheating
What component maintains correct ignition timing in modern engines?
A. Ignition coil
✔✔B. Engine control module (ECM)
C. Fuel rail
1
,D. Camshaft sensor
Which sensor monitors the position of the crankshaft?
✔✔A. Crankshaft position sensor
B. Oxygen sensor
C. Knock sensor
D. Oil pressure sensor
If an engine stalls shortly after starting, what is a likely cause?
✔✔A. Faulty idle air control valve
B. Clean spark plugs
C. Excessive fuel pressure
D. Cool radiator
A stuck open thermostat will likely cause:
✔✔A. Engine running below optimal temperature
B. Overheating
C. Engine knocking
2
,D. Fuel injector damage
What is the function of a PCV (positive crankcase ventilation) valve?
✔✔A. To vent combustion gases from the crankcase
B. To control fuel injection
C. To increase oil pressure
D. To regulate spark timing
Which reading on a compression test would suggest a healthy cylinder?
A. 50 psi
✔✔B. 160 psi
C. 30 psi
D. 90 psi
A spark plug with black, sooty deposits may indicate:
✔✔A. Rich fuel mixture
B. Lean mixture
C. Coolant leak
3
, D. Cracked head gasket
What is one purpose of a catalytic converter?
A. Increase engine power
✔✔B. Reduce harmful exhaust emissions
C. Store exhaust gases
D. Cool the exhaust system
A technician finds metal shavings in the engine oil. What is the likely cause?
✔✔A. Internal engine wear or damage
B. Faulty fuel pump
C. Rich air-fuel mixture
D. Vacuum leak
Why might an engine crank but not start?
A. Low oil level
B. Dirty cabin air filter
✔✔C. No spark or no fuel delivery
4
