What Causes the Engine to Feel Sluggish and Not Accelerate When Throttling?

[McDaisy]

The reasons for the engine feeling sluggish and not accelerating when throttling include carbon buildup issues and intake problems. Below are the detailed explanations for these causes: Carbon Buildup Issues: Carbon buildup can occur in the cylinders, throttle body, spark plugs, and intake manifold—areas that are directly related to the engine's power output. When there is excessive carbon buildup inside the engine, the vehicle's ignition energy decreases, and intake efficiency drops, ultimately leading to reduced engine power, resulting in sluggish acceleration and a muffled sound. Intake Problems: Air is one of the engine's power sources. If the air filter becomes clogged due to prolonged use without timely cleaning, insufficient air supply will cause the air-fuel mixture to become too rich, reducing engine power. For vehicles equipped with turbochargers, if the turbocharging system malfunctions, even when the throttle is applied, the engine will remain sluggish and fail to deliver strong performance.