Is it normal for the fuel pump to keep running when the key is turned on?
2 Answers
It is normal for the fuel pump to keep running when the key is turned on. After the vehicle is powered on, the fuel pump starts working, and at this time, the fuel pump will produce noise. If the fuel pump does not make any noise after powering on, that indicates a malfunction. There is an important component in the car's fuel supply system, which is the fuel pump. The fuel pump can create fuel injection pressure. Without the fuel pump, there would be no fuel injection pressure. If the fuel pump fails, the engine cannot be started. When starting the engine, the ignition system, fuel supply system, and starter all need to work. The ignition system mainly consists of spark plugs and ignition coils.
Regarding the issue of the fuel pump continuously running when turning the key, this is definitely abnormal. Under normal circumstances, when you turn the key to the "on" position, the fuel pump (usually the electric fuel pump) will only buzz briefly for a few seconds to build up fuel pressure, then it automatically stops. If it keeps humming non-stop, there's likely a problem. Common causes include a malfunctioning fuel pump itself—such as an internal motor getting stuck or clogged with debris—or electrical issues like a stuck relay causing continuous current flow, or a wiring short preventing the pump from shutting off properly. I've repaired many vehicles where owners ignored this symptom, only to experience sudden engine stalls while driving, fuel pump overheating damage in high temperatures, or even dangerous fuel line leaks. My advice: don't drive immediately. First, try identifying the noise source in a quiet environment. If the sound persists, visit a professional repair shop immediately. Safety first—never delay. Regular maintenance can prevent such issues.
