Problems with the fuel pump pressure emerge when the pump is unable to keep the necessary pressure to supply constant fuel delivery to the engine, affecting performance and reliability. Most factory pumps run in the 40-60 PSI range, which allows the engine to pull in enough air to get the right amount of fuel for complete combustion. If the pump fails to keep this pressure, the flow of fuel becomes pulsed, which leads to issues like engine misfires, jerks, and ineffective acceleration. Even a small pressure drop of 10% can disrupt the ratio of the air-fuel mixture, causing a lean condition that can generate knock and decrease efficiency.
A failing pump usually suffers from internal wear, or electrical issues or a blockage in a fuel line leading to low pressure. The impeller or motor brushes can wear down and fail to produce sufficient pressure, leading to a 20% lower fuel flow in high demand situations. Inconsistent pressure and overheating are caused by voltage dropping below the standard 12 volts. The pump has to work harder when electrical problems arise. Most mechanics will suggest checking the condition of the fuel pump relay and wiring for any looseness as a slight 5% decrease in voltage can cause the pump to fluctuate.
High fuel pressure can also be a sign of failure, and is typically associated with a faulty pressure regulator. If the pressure regulator doesn’t relieve excess fuel pressure, it can cause excessive line pressure as well, stressing the pump and potentially causing leaks of even component damage. A stuck regulator could also be a death sentence for performance engines that may need pressure levels greater than 100 PSI, and as a result the pump overheats or dies an early death. In such scenarios, undergoing routine inspection of the pressure regulator avoids any issue which can hamper the lifespan of any other components in the fuel system.
Pressure problems may become worse because a clogged fuel filter or fuel line can cause pressure drops as the pump has to work harder to push fuel through the blockage. If all these filters are clogged it can reduce the fuel flow by as much as 15 percent, which in turn puts pressure on the pump and doesn`t help the overall efficiency. Fuel Filters – Replacing fuel filters every 20,000-30,000 miles allows a free flow of fuel, minimizing pressure issues and helps to prolong the life of a Fuel Pump.
By taking care of the fuel pump pressure problem without delay the engine will get a consistent fuel supply keeping performance intact and preventing expensive repairs due to lower amount of fuel to the engine. Routine maintenance of the fuel system is paramount for the reliability of the vehicle, because constant pressure is a must for engine health and optimal combustion.