Fuel pump flow dictates the amount of fuel available to the engine; having the proper amount of fuel per the engines needs is critical for performance, efficiency, and longevity. Most fuel-injected engines require a flow rate between 40-70 PSI for proper combustion. If the pump isn’t able to maintain this flow, the engine will run lean, which will result in a rough idle, misfires, or overheating experiences. Lack of fuel flow means operating on the lean side of the combustion fence, with added risks of poor combustion and potential damage to the engine due to inadequate cooling and power loss.
Turbocharged and high-performance engines have even more stringent fuel pump flow requirements. For example, vehicles with engines capable of producing more than 400 hp typically need pumps with flow rates exceeding 255 liters per hour (LPH) to cover their greater demand for fuel under a hard acceleration or at full load. If fuel flow does not meet these demands, the air-fuel ratio within the engine gets out of whack, and combustion cycles that produce 10-15% less power than possible during this misbalanced ratio rely on something else, such as inefficient combustion cycles. Tests done at the track show that motors using high-flow fuel pumps have a much more stable air-fuel ratio, which is as critical in preventing knock — where the fuel detonates sooner than intended when the piston is at the top of the travel cycle, and the parts of the motor start to wear down quickly.
Even fuel injectors need a steady flow of fuel for proper pump timing since the injectors depend on regular flow to time the moment when fuel enters the combustion chamber. Intermittent fuel flow impacts the engine control unit (ECU) and prevents it from controlling injection timing properly leading to poor throttle response, lower fuel economy and increased emissions. Automotive expert Ed China says: “Stable fuel flow is a cornerstone for a reliable fuel system and a direct influence on engine performance. This emphasizes the importance of fuel flow for the health and health of the engine line.
Low temperatures obviously have an effect on fuel pump flow as well. Fuel pumps can also overheat, which causes lower flow rates and pump failure in extreme situations, in hot climatic conditions and high load. Pumps that have cooling feature, like heat resistance and heat dissipating design are manufactured to maintain the flow established at extreme temperatures. In those scenarios, a high-performing pump that can withstand extreme heat provides an additional 30 percent service life due to fewer repairs while maintaining constant fuel flow for the vehicle.
And lastly, fuel flow needs to be maintained for ensuring fuel economy and emissions. The incomplete combustion produced by lean conditions caused by lack of good fuel flow generates more pollutants than the miles per gallon that is saves. So, a good quality Fuel Pump that is specific to the needs of your vehicle enables more efficient and cleaner fuel use, consistent emissions, and optimal performance, but it is also a major factor in the engine longevity and reliability.