Basically, Fuel Pump can work without stoppage for long hours if the operations are within the specs that require the manufacturer and if the conditions are good. Most of the Fuel Pumps can last about 100,000 to 150,000 miles under normal use, which equates to several thousand hours of continuous operation. In truth, however, the coolness of fuel, operating temperatures, and if the pump is submerged in the fuel are factors that help keep it cool. This factor more than others will dictate how long it really will last and can keep running.
Fuel Pumps are designed to run as long as the engine is running so in situations like long road trips or heavy duty applications they can operate for 8-12 hours at a time without issue. Since In-tank Fuel Pumps are submerged in gasoline, they are kept cool by the fuel itself and can run for very long times efficiently. Driving the vehicle with a low fuel level too often overheats the pump, reducing its lifespan.
The recalls that began in 2019 year included more than 700,000 vehicles by Toyota due to defective Fuel Pumps causing stall and power loss after continuous use especially in a high-temperature environment. That means how much external factors like heat and levels of fuel could affect a fuel pump to continue running for longer periods.
In high-performance cars with high-flow aftermarket Fuel Pumps like Walbro 450 LPH, continuous operation under extreme load is not a problem with the pump, provided the fuel system is maintained appropriately. These are pumps designed for racing or high-performance driving, where they may be required to operate under high load for long durations without failure.
As David Vizard, one of the most qualified authorities on all automotive matters, has said, “A well-cared-for fuel system may run for hours, but if neglected, it will fail prematurely.” Keeping your Fuel Pump in good working condition by regular maintenance, maintaining high levels of fuel, and avoiding contaminants in the fuel can go a long way in extending the life of the pump to support its continuous operation.
For more detailed information about how to keep your Fuel Pump in top working order, see Fuel Pump.