POSTAL AUTOMOTIVE TECHNICIAN
EXAM 944 | ACTUAL EXAM
QUESTIONS AND 100% CORRECT
ANSWERS | A GRADE (2026/2027)
This Postal Automotive Technician Exam 944 is an assessment used by the
USPS to test mechanics on diagnostic procedures, engine systems, and electrical
components. Below is a high-yield breakdown of key questions and verified
answers in this test prep modules.
Engine Systems & Mechanics
• Vibration damper: Fastened to the crankshaft.
• Leaking intake valve guides: Will cause excessive oil consumption.
• Carbon fouling of a spark plug: Indicates too rich a mixture.
• Diesel engine ignition: Fuel is ignited by the heat of compression.
• Flooding of a carburetor: Generally caused by a stuck float needle
valve.
Steering & Suspension
• Rod adjustments on a car: Affects toe-in.
• Added cornering stability device: Called a stabilizer bar.
• Ball joint front suspension: Eliminates the conventional kingpin.
, • Excess tire wear on edges: Most common cause is underinflation.
Brakes & Electrical
• Soft brake pedal: Generally, the result of air in the lines.
• Disc vs. drum brakes: Disc brakes have the advantage of fading less
when hot.
• Polarizing a generator: Prevents damage whenever the generator or
regulator wires have been disconnected.
• Testing a storage battery: Most reliable method is using a hi-rate
discharge cell tester.
• Ignition point burning: Generally, the result of a faulty condenser.
Q1. Most small gas engines use which type of ignition system? [Multiple Choice]
A) Magneto
B) Battery-coil system
C) CDI system
D) Distributor ignition
Answer: Magneto
Explanation: Many small gasoline engines are self-contained and use a magneto ignition that
generates high voltage without a battery; the magneto produces sparks as the engine turns. A
battery-coil system relies on a battery and coil and is typical in larger automotive systems. CDI
systems are common in motorcycles and some small engines but are separate technology from a
, simple magneto. A distributor is part of a battery-coil ignition system, not the standalone
magneto arrangement.
Q2. What does carbon fouling of a spark plug indicate? [Multiple Choice]
A) Too rich a mixture
B) Excessive ignition timing
C) Overheating engine
D) Air leak in intake manifold
Answer: Too rich a mixture
Explanation: Carbon fouling forms when fuel does not burn completely, leaving carbon deposits
on the spark plug; excessively rich air–fuel mixtures supply too much fuel and promote this
incomplete combustion. Excessive ignition timing tends to cause overheating or preignition
rather than pure carbon fouling. An overheating engine produces glazed or burned deposits but
not the same carbon soot buildup. An air leak in the intake would make the mixture leaner, which
usually causes misfires or higher combustion temperatures, not carbon fouling.
Q3. The vibration damper on an auto engine is fastened to the: [Multiple Choice]
A) Crankshaft
B) Camshaft
C) Valve cover
D) Transmission
Answer: Crankshaft
Explanation: A vibration (harmonic) damper is attached to the crankshaft to reduce torsional
vibrations produced during engine rotation; mounting it on the crankshaft lets it directly
counteract those twisting forces. Camshaft is driven by the crankshaft and is not the primary
mounting point for the damper. Valve cover is a non-rotating cover over the valve train and
EXAM 944 | ACTUAL EXAM
QUESTIONS AND 100% CORRECT
ANSWERS | A GRADE (2026/2027)
This Postal Automotive Technician Exam 944 is an assessment used by the
USPS to test mechanics on diagnostic procedures, engine systems, and electrical
components. Below is a high-yield breakdown of key questions and verified
answers in this test prep modules.
Engine Systems & Mechanics
• Vibration damper: Fastened to the crankshaft.
• Leaking intake valve guides: Will cause excessive oil consumption.
• Carbon fouling of a spark plug: Indicates too rich a mixture.
• Diesel engine ignition: Fuel is ignited by the heat of compression.
• Flooding of a carburetor: Generally caused by a stuck float needle
valve.
Steering & Suspension
• Rod adjustments on a car: Affects toe-in.
• Added cornering stability device: Called a stabilizer bar.
• Ball joint front suspension: Eliminates the conventional kingpin.
, • Excess tire wear on edges: Most common cause is underinflation.
Brakes & Electrical
• Soft brake pedal: Generally, the result of air in the lines.
• Disc vs. drum brakes: Disc brakes have the advantage of fading less
when hot.
• Polarizing a generator: Prevents damage whenever the generator or
regulator wires have been disconnected.
• Testing a storage battery: Most reliable method is using a hi-rate
discharge cell tester.
• Ignition point burning: Generally, the result of a faulty condenser.
Q1. Most small gas engines use which type of ignition system? [Multiple Choice]
A) Magneto
B) Battery-coil system
C) CDI system
D) Distributor ignition
Answer: Magneto
Explanation: Many small gasoline engines are self-contained and use a magneto ignition that
generates high voltage without a battery; the magneto produces sparks as the engine turns. A
battery-coil system relies on a battery and coil and is typical in larger automotive systems. CDI
systems are common in motorcycles and some small engines but are separate technology from a
, simple magneto. A distributor is part of a battery-coil ignition system, not the standalone
magneto arrangement.
Q2. What does carbon fouling of a spark plug indicate? [Multiple Choice]
A) Too rich a mixture
B) Excessive ignition timing
C) Overheating engine
D) Air leak in intake manifold
Answer: Too rich a mixture
Explanation: Carbon fouling forms when fuel does not burn completely, leaving carbon deposits
on the spark plug; excessively rich air–fuel mixtures supply too much fuel and promote this
incomplete combustion. Excessive ignition timing tends to cause overheating or preignition
rather than pure carbon fouling. An overheating engine produces glazed or burned deposits but
not the same carbon soot buildup. An air leak in the intake would make the mixture leaner, which
usually causes misfires or higher combustion temperatures, not carbon fouling.
Q3. The vibration damper on an auto engine is fastened to the: [Multiple Choice]
A) Crankshaft
B) Camshaft
C) Valve cover
D) Transmission
Answer: Crankshaft
Explanation: A vibration (harmonic) damper is attached to the crankshaft to reduce torsional
vibrations produced during engine rotation; mounting it on the crankshaft lets it directly
counteract those twisting forces. Camshaft is driven by the crankshaft and is not the primary
mounting point for the damper. Valve cover is a non-rotating cover over the valve train and
