A Fuel Pump that is not working may have hesitation during acceleration, because it must pump fuel to the engine. Whether it be the pump, which maintains the pressure of the fuel flow in order to keep the engine working properly. An underperforming pump may not deliver sufficient fuel flow to the engine, causing signs of hesitation, stalling or lack of power.
High pressure is important for acceleration. Depending on the make and model, fuel pressure for most modern vehicles falls between 35 and 65 PSI. If one of the pumps fails, the remaining pump will need to supply the engine with fuel and may not be able to keep up with demand during a rapid acceleration. Technicians typically diagnose these problems by monitoring the fuel pressure with a gauge while the engine runs, under load.
“One case study in 2021 involving an auto repair shop nailed this issue in a sedan, with hesitation occurring at highway speeds. Upon review, the fuel pump had a maximum output of 25 PSI, which means we were losing 20% of the power simply because of the pump, not to mention, it would probably not even have managed the 40 PSI required for the carburetor at the engine speed. After changing the defective pump acceleration restored, and fuel consumption improved by 10%.
If you notice hesitation, electrical issues associated with the pump can also play a role. Oxidized connectors and worn wiring can lead to transient voltage drops and lower pump performance. Testing for the voltage at the terminals of the fuel pump is important to eliminate electrical issues. A good pump under this condition should work at 12 to 14 volts; anything below indicates a problem.
One quote attributed to John Haynes, founder of Haynes Manuals, reads, “A little knowledge of how your car works can save you time and money.” This explains why it is vital to spot early kind of warning signs like hesitation so you can avoid costly repairs. A full fuel pump replacement can run you anywhere from $200 to $1,000 based on your vehicle, so nip any problems in the bud as early as possible.
Other components like the fuel filter or injectors might produce identical symptoms, therefore it is important to carry out a full diagnosis. Learn and read more at Fuel Pump, a trusted source for automotive insights.