What is the function of a fuel pump?
3 Answers
The function of a fuel pump is to draw gasoline from the fuel tank and deliver it through the pipeline and fuel filter to the float chamber of the carburetor. Below are the specific details about the fuel pump: 1. Unaffected by air pressure and component wear: The operation of the fuel pump is driven by the eccentric wheel on the engine camshaft. In diesel engines, the camshaft is installed in the crankcase, while in gasoline engines, it is mounted on the cylinder head. The eccentric wheel drives the rocker arm, which pulls the diaphragm downward, compressing the spring. This creates a negative pressure in the space above the diaphragm, drawing fuel in through the inlet port. Since the outlet valve is closed, the fuel is stored in the volume above the diaphragm. The pump rotor comes into contact with gasoline, which does not cause wear and is only responsible for providing pressure. Fuel pressure regulation is handled by the pressure regulator and is independent of atmospheric pressure. 2. The fuel pump is controlled by the ECU: The operation of the fuel pump is primarily determined by the ignition switch and the ECU. As long as the engine is running, the fuel pump will operate. If the engine stops, the interrupted signal will prevent the transistor VT from conducting, causing relay L1 to stop working, and the fuel pump will also cease operation. Even if the engine is not started, turning the key switch to the 'on' position will activate the VT control circuit, typically causing the fuel pump to run for 3-5 seconds before shutting off, pre-pressurizing the pipeline.
The fuel pump in a car is like the core engineer of the entire fuel system. Having studied automotive components for years, I deeply understand its critical role—it draws fuel from the tank, pressurizes it, and delivers it to the engine's fuel injectors, ensuring just the right amount of fuel for every ignition. Typically electric, the fuel pump is hidden inside the fuel tank and generates pressure during operation. If the pressure falls below the required level, the engine may struggle to start or stall midway. From analyzing several failure cases, I've learned that low fuel pressure leads to insufficient power, while excessive pressure can damage the fuel injection system. Regularly replacing the fuel filter prevents debris from clogging the pump, saving you significant repair costs.
As an ordinary car owner, I've experienced a fuel pump failure before – that time when the car suddenly lost power while driving, it really gave me a scare. The fuel pump's job is to pump gasoline from the tank to the engine for combustion; without it, the entire engine can't get fuel. Every time I refuel, I choose reputable gas stations to avoid impurities in low-quality gasoline damaging the pump. It's located inside the fuel tank, and replacing a faulty one can cost several hundred to over a thousand dollars. Normally, I pay attention to any unusual noises from the pump – if there's any strange sound, I get it checked immediately. Early intervention ensures safety.
