Another good sign when determining if a fuel pump needs to be replaced is if a vehicle can no longer hold consistent power, particularly when under load or when accelerating. While standard gas pumps can get to in the ballpark of 100,000 miles, the quality of the fuel and the vehicle’s maintenance can make a difference. If the fuel pump has a hard time of things, and the fuel delivery rate drops by 30%, the engine might stall, misfire, or just run at much less than optimal performance and economy.
Fuel pumps are probably somewhere in the 30 to 80 psi range, depending on the automobile. A rapid decline in available fuel pressure, easily detectable with a plumbed-in fuel pressure gauge, will lead to insufficient ignition and combustion, and promised power and efficiency will go with it. It’s best to check this early, as continued running of a failing pump can lead to expensive engine repairs if it runs out of fuel, or complete fuel system replacement — something most mechanics will advise not to wait on.
Case in point, there have been many fuel pump related recalls in the automotive sector. More recently, in 2019, both Toyota and Subaru recalled thousands of vehicles over defective fuel pumps that did not provide enough pressure, causing the engine to stall unexpectedly. Simply put, time spent in a vehicle that lacked fuel delivered consistently and at the correct pressures — or, in the words of ASE-certified technician and co-owner of Seyfer Automotive, Donny Seyfer, “That would be like trying to run a marathon without water.”
Difficulty starting the vehicle, sputtering at high speeds, and lack of power can also be signs of a failing pump. These symptoms typically correlate with decay of the fuel pump, which has an associated reduction of output and effective life. Even if his diagnosis is right on the mark, the average fuel pump replacement costs between $400–$600 with the latter making up an additional $100–$200 in labor charges, so it pays to catch the problem early.
A pump can only work effectively if the fuel used to run them is of high quality, and one should not allow his or her tank to run below the quarter mark, as low fuel may trigger the overkill of the pump thus affecting its health. Keeping the tank at least half-full more often helps keep immersing the fuel pump, improving its cooling and extending its life.
Learn more about what fuel pump does and why you might need to replace it in this Fuel Pump resource .