The fuel pump is the heart of the fuel system, and its function is to transfer fuel from the tank to the engine at the correct pressure. The modern fuel-injected vehicles use a Fuel Pump that operates within a range of 40 to 60 PSI, thereby ensuring fuel delivery to the injectors through a constant flow. This ensures smooth fuel delivery, which becomes a major influencing factor in performance, efficiency, and emissions concerning the air-fuel ratio in the engine.
Most vehicle fuel pumps are submerged in fuel inside the fuel tank to cool the pump and prolong its life. The pump draws fuel from the tank and pushes it through the fuel lines to the fuel injectors, which atomize the fuel for combustion in the engine. This process is constant in running the engine. The Fuel Pump adjusts to the demand of the engine. Higher specification Fuel Pumps, such as the Walbro 450 LPH, are installed in high-performance cars and highly modified engines to support higher horsepowers by delivering more fuel at higher pressures.
In some instances, fuel systems also include a fuel pressure regulator, which works to maintain the appropriate pressures of the system to ensure that the engine is not running too rich or too lean. If the Fuel Pump does not maintain adequate pressure, then the fuel injectors do not deliver the proper amount of fuel for good combustion; hence leading to reduced power and possible damage to engine components.
In 2018, General Motors recalled over 1.2 million vehicles due to defective Fuel Pumps, which caused interruptions in the fuel system and further led to stall-outs and a loss of vehicle power. The above example gives an idea of the importance of the fuel pump in the overall functionality of the fuel system and the reliability of the vehicle.
As Automotivie engineer David Vizard said, “The fuel system is only as strong as its weakest link,” and the Fuel Pump is undeniably one of the most vital pieces.
For further details regarding how the Fuel Pump integrates into your car’s fuel system, see Fuel Pump.