Q: Fuel pump start working and makes noise with the engine switched off

Hi there:

Every time you turn on the ignition of your car, you activate the fuel pump relay. This device sends an electric current to the fuel pump. Upon receiving this current, the fuel pump sends gasoline to the engine and the car starts running. While the fuel pump is active as long as the car engine is running, the fuel pump relay works only at startup and when you turn off the ignition. However, if there is damage to the relay, it will run constantly; as you’re question indicates. You should contact a professional mechanic to更换燃油泵继电器在发生进一步损害之前，请尽快。