Basically, the role of a fuel pump is to regulate the flow of fuel by pumping the fuel from the tank towards the engine at a particular pressure and volume. On most of the new models, the ones that run fuel-injected engines do so by running the Fuel Pump within a pressure range of 40 to 60 PSI to make sure the proper quantity of fuel reaches the engine for proper combustion. Consequences of low pressure include reduced fuel flow, which can be accompanied by a lean fuel mixture resulting in misfires, poor acceleration, or overheating. The other way around, too much fuel pressure will always flood the engine and lead to the inefficient combustion of fuel, ultimately affecting fuel economy.
Fuel flow is directly related to the flow rate of the pump, measured in liters per hour (LPH). For example, a standard Fuel Pump can handle 255 LPH, which is sufficient to serve engines running on not more than 500 horsepower. High-performance vehicles require higher levels of fuel flow for maintaining high power output. For such applications, high-flow Fuel Pumps such as Walbro 450 LPH increases the fuel flow amount and could easily support engines running more than 600 horsepower. If it does not get the proper amount of fuel, a performance engine is at the risk of fuel starvation, and it can badly damage the engine over a period of time.
A very important example can be viewed in the 2019 Toyota recall of over 700,000 vehicles equipped with faulty fuel pumps. These Fuel Pumps were unable to provide adequate fuel pressure, which caused stalling and loss of power during driving. In this event, one could tell the importance of a good Fuel Pump in order to maintain consistent fuel flow and overall reliability in the vehicle.
Furthermore, fuel economy could also depend upon the efficiency of the fuel pump. In such cases, where the pump fails to maintain proper flow at desired pressure, the engine may have to work harder. That may drastically increase fuel consumption. The balance between fuel feeding and consumption could potential lower the overall efficiency of the working of the engine and inflate operating cost in the long run.
As the great automotive mind David Vizard once stated, “A well-matched Fuel Pump is to an engine’s health and performance as one’s lifeblood”. Getting the correct quantity of fuel at the correct pressure via the Fuel Pump is absolutely crucial for both longevity and efficiency.
For more on selecting the right Fuel Pump see Fuel Pump.