Why does the car's speed not increase when stepping on the accelerator, but the RPM goes up?

[VanLorenzo]

Possible reasons for the car lacking power and unable to accelerate include: 1. Ignition system failure, such as aging ignition coils or spark plugs that haven't been replaced for a long time, leading to insufficient ignition energy, poor combustion, weak engine acceleration, and the engine warning light turning on. 2. Fuel system failure causing excessively low pressure. Insufficient fuel injection can result in weak engine acceleration. 3. Excessive engine carbon deposits, leading to poor fuel atomization, which also causes poor combustion, excessive exhaust emissions, and weak engine acceleration. 4. Engine system failure, causing the engine to enter an emergency operation mode, thereby limiting engine power output and resulting in weak acceleration. Examples include engine sensor failures, such as oxygen sensors, air flow meters, crankshaft position sensors, knock sensors, etc. Faulty signals from these sensors can cause the engine to enter emergency operation mode, leading to weak acceleration. 5. Damaged catalytic converter or turbocharger. When such issues occur, it is necessary to visit a repair facility to diagnose related fault codes using a computer and troubleshoot based on the fault codes.