Most cars will operate within a range of 12 – 14 volts for most functions, with a fuel pump being no exception. The vast majority of automotive fuel pumps work best when they receive 13.5 volts, because this voltage allows a pump to sustain the correct amount of pressure as demands placed on an engine change based on various conditions enforced by gas-saving or performance (otherwise operating at peak efficiency). If the voltage is too low, fuel pressure will decrease and a drop in performance or possibly misfires could occur; if it's too high, pump components can wear prematurely (five to 10 years).
Voltage stability in these high-performance situations directly affects the flow rate of the pump, typically rated in liters per hour (LPH). Notably, a 13.5-volt fuel pump generally will produce at least 200 LPH or more to handle most common engines. Higher-pressure-flow fuel pumps for high-horsepower engines might require power supply systems that can provide a minimum of 14-volt under load due to the increased demand for fuel. According to Bosch, a major automotive system supplier recommended it for maintaining the correct voltage level in order to prevent overheating and fuel cavitation so that reliable supply of fuel could be guaranteed.
Modern vehicle fuel pumps are often pulsated with regulator controlled circuits that vary the voltage to support engine demand; To minimize fuel waste, limit greenhouse gas emissions and maintain compliance with U.S. or California Air Resource Board (CARB) emission system standards this regulation of voltage control works in unison with the US/National Setting EPA/CARB/Standard Process regulations for backup battery systems commonly found on GEN 1 models. For comparison, the decrease in efficiency for a pump is at least 7-8% according to industry data due random voltage fluctuation – as much as 15%, and we did not even throttle it!
Things like bad grounding or corroded connections in vehicles with electrical issues can decrease the voltage to which the fuel pump operates on, making it less durable and needing more replacement. Mechanics and serious "DIY" automotive types generally test voltage on a regular basis with multi meters to verify the system is getting 12-14 volts continuously following delivery, if not troubleshooting pending. In other words, in the famous[3]words of Henry Ford: "Quality means doing it right when no one is looking," because getting fuel pump voltage maintained as close to reality helps vehicle performance.
If the voltage supplied to varies greatly from what is needed for certain driving conditions or heavy loads, may not pump enough fuel and cut off airflow in high-speed operation halting an engine, reduce performance akin a failed. The voltage supply weakness emphasizes the necessity of high-quality wiring and electrical systems that can deliver constant power. Modern diagnostics from companies such as Delphi have advanced enough to even include voltage monitors for the purposes of guaranteeing steady amounts of fuel available.
For more information on Fuel Pump voltage requirements and their effect performancevisit, Fuel Pump for a complete overview of the reaction by different voltagesand specifications about needed measurements- maintenance systems fuel.