What are the reasons why the car's tachometer fails to rise at high speeds?
2 Answers
Specific reasons why the engine speed fails to rise at high speeds: 1. Fuel injector malfunction, uneven fuel injection causing an imbalance in power output among cylinders. This can be due to clogged injectors, poor sealing, or fuel spraying in a linear pattern. 2. Incorrect fuel injection quantity, caused by sensor or wiring faults, leading the control unit to issue incorrect commands. This results in either too rich or too lean a fuel mixture, indirectly causing unstable idling. 3. Oxygen sensor failure, including open circuits, short circuits, or grounding faults in the sensor wiring, or poor contact in the engine control unit plug due to water ingress or internal faults.
As an ordinary car owner, I have also encountered the annoying issue of the tachometer not rising; for example, once when accelerating on the highway, I pressed the accelerator deeply but the RPM didn't move. Later, I found out it was due to insufficient transmission fluid causing slippage. Similar problems can also arise from clutch wear, which prevents effective power transmission, or fuel system blockages such as fuel pump failure or injector carbon buildup, limiting fuel supply. Additionally, a dirty air filter can obstruct air intake, making it difficult for the engine to breathe smoothly. In such cases, it's best not to force the drive. Stop the car in time, use simple tools to check the fluids, and then have a mechanic handle it.
