After c4 Sega started, the tachometer suddenly turned so fast when stepping on the gas pedal.

The reasons for the sudden increase of the tachometer are as follows: 1. If the cylinder pressure is insufficient, you can check the wear of the piston ring and piston; There is something wrong with the oil. It is recommended to replace the oil with good quality; 3. The air intake system fails, and the throttle opening suddenly increases; 4. The air-conditioning clutch slips or is damaged, and the engine suddenly loses load, resulting in an increase in speed; 5. It is caused by the forced downshift of the gearbox computer, or there is a fault inside the gearbox and the output power of the engine is insufficient. This needs maintenance.