Why does the engine idle normally but lack power when running?

[McLyla]

Here is the relevant introduction to the situation where the engine idles normally but lacks power when running: Carbon buildup in the vehicle: There are three reasons for the car's lack of acceleration power. The first is carbon buildup in areas such as the valves, idle control valve, intake manifold, combustion chamber, and spark plugs. Insufficient fuel supply is caused by severe clogging of the fuel injectors. Poor fuel quality: One of the most important reasons for a car's lack of acceleration power, which many car owners experience, is the use of poor-quality fuel. This can affect the fuel filter and fuel lines, potentially leading to inadequate fuel supply and resulting in a lack of acceleration power.