What to Do When Ford Focus Has Poor Acceleration, Dull Sound, and Loud Noise?

[SanSabrina]

Many people believe that throttle carbon buildup can affect engine acceleration performance. However, valve carbon buildup mainly causes unstable idling and has little impact on engine acceleration performance. A clogged or waterlogged air filter can reduce airflow, leading to an overly rich air-fuel mixture, incomplete combustion, poor acceleration, and severe black smoke from the exhaust pipe. Insufficient fuel pump pressure can cause poor fuel supply, resulting in weak acceleration. Poor fuel injector atomization can lead to uneven cylinder operation or misfiring, affecting acceleration performance. A faulty mass airflow sensor can reduce intake air volume, causing an overly rich or lean air-fuel mixture, which impacts acceleration performance. Additionally, a damaged spark plug in an individual cylinder can also affect acceleration.