Electrical system powers the fuel pump in a car, and it requires an appropriately charged battery for proper functioning; if low, then the fuel pump does not get full power, thus low fuel pressure, which directly affects the performance of the engine. In most vehicles, fuel pumps operate best on at least 12 volts of voltage. This is because, if the battery falls below that threshold, it may not be able to sustain the required 40 to 60 PSI of fuel pressure, thus creating problems such as hard starting, stalling, or rough idling.
Where the battery is only partially discharged, on those vehicles, the Fuel Pump may still work, albeit at suboptimal levels. A weak battery may translate to a low volume of fuel flow, and such an arrangement could lead to an engine running lean: when more air is present than fuel in the combustion mixture. This can result in overheating, or eventual damage to components over a period of time. Too low of a battery will result in the pump possibly not working at all, barring an attempt to start the engine.
Specifically, a study in 2019 established that 25% of the vehicles experiencing problems with fuel delivery were electrically faulty due to low voltage in the battery; this proves the direct relationship between the condition of the battery and the working of the Fuel Pump. The Fuel Pump needs a fully working battery to pump the appropriate amount of fuel for proper performance of the engine.
The Walbro 450 LPH high-performance fuel pumps are even more sensitive to a properly operating electrical system, as they were designed to give out more quantity of fuel. If the battery voltage isn't good enough, such high-flow pumps may fail to meet the requirements of the engine for fuel, particularly under acceleration or heavy loads.
As David Vizard, a highly recognized automotive expert, has pointed out, "Fuel system efficiency is tied directly to electrical health-if the battery can't supply the power, the fuel won't flow." By regularly checking the health of the battery, one makes certain efficiency in the operation of the Fuel Pump and helps avoid fuel-related performance issues.
For more information about keeping your Fuel Pump running and its proper operational mechanism with battery voltage, head over to Fuel Pump.