Fuel Pump problems can cause too much fuel to be used as it disrupts the accurate fuel delivery needed for an engine to run efficiently. The ideal air-fuel mixture is critical to modern fuel injection systems, and that requires consistent fuel pressure delivered to the injectors — normally 35 to 65 PSI. If one of the pumps in such a system fails and either does not deliver anything at all, or any amount of fuel other than what the engine needs, this balance gets off track, causing inefficient combustion and increased consumption of fuel.
When there is more fuel from the pump than the engine needs, the engine “runs rich,” burning the extra fuel inefficiently. That leads to lost fuel and higher emissions. In a 2022 study on automobiles, it showed that the vehicles with broken fuel pumps of any kind were running their fuel consumption up by 20%, either over-delaying or under-delivering.
Another potential cause of excessive fuel use is a damaged fuel pump regulator. The regulator maintains a certain pressure inside the fuel rail. If it goes wrong, the pump might send uncontrolled amounts of fuel to the engine, reducing efficiency further. This will frequently set diagnostic trouble codes like P0172 (System Too Rich) or P0193 (Fuel Rail Pressure Sensor High Input) that can be read from an OBD-II scanner.
In real-world cases, failed fuel pumps can take a serious toll on fuel economy. A 2023 sedans were diagnosed with a bad pump delivering the fuel at 80 PSI when the engine needed more like 30. When the pump was replaced, pressure was back to normal, and fuel consumption improved by a quarter and emissions dropped.
Routine maintenance, including checking the fuel pump, can avert these problems. Most fuel pumps last between 100,000 and 150,000 miles, but things like contaminants or a clogged filter can prevent them from lasting that long. Replacing the fuel filter — at a cost of $20 to $50 — every 20,000 to 30,000 miles can help prolong pump life and prevent over-delivery issues.
“If everyone is moving forward together, then success takes care of itself” —Henry Ford This, together with regular maintenance and timely diagnostics, ensures that all vehicle components — fuel pump included — work harmoniously to achieve optimal performance and fuel economy.
Learn more about keep a fuel pump and how to repair fuel pumpproblem at Fuel Pump.