FAA Powerplant Written Practice Test

How does a faulty capacitor affect ignition performance?

1. It prevents fuel from igniting

2. It causes inconsistent sparks

3. It increases engine noise

4. It reduces overall efficiency

The correct answer is: It causes inconsistent sparks

A faulty capacitor affects ignition performance primarily by causing inconsistent sparks. In internal combustion engines, the ignition system relies on a properly functioning capacitor, or condenser, to store and release energy to create a strong spark at the spark plugs. If the capacitor is faulty, it may not hold the charge efficiently or may release it inconsistently. This results in erratic performance, where the spark may either be too weak to ignite the fuel-air mixture or may not occur at the correct timing, leading to potential misfires or rough engine operation. While other options may touch on various aspects of engine performance, they do not directly relate to the specific role of a capacitor in the ignition system. In summary, the importance of a functioning capacitor lies in its ability to maintain consistent spark generation, which is crucial for efficient combustion and overall engine smoothness.