If the fuel pump is not able to provide adequate pressure, there are several ways through which the problem can be resolved. In most instances, the first sign of low fuel pressure usually manifests as engine misfires or poor starting of the vehicle, which can be traced from the fuel pump, failing to deliver adequate fuel flow. According to a Bosch study, fuel pumps that run below optimal pressure can cut down the engine’s power by up to 25%, resulting in poor fuel economy and even engine stalling.
The first thing that should be checked is the fuel pressure regulator, which is responsible for maintaining pressure in the fuel system. A faulty fuel pressure regulator can result in extreme loss of pressure. In a Ford F-150, for example, a bad fuel pressure regulator can drop the fuel pressure from 55 psi down to less than 30 psi, which is well below the minimum requirement for standard engine operation. Replacing the regulator may restore the system to its designed pressures.
Next, take a reading of the fuel pressure with a fuel pressure gauge. This is a diagnostic tool that gives an accurate reading to help in determining if the pump is failing or if there is another problem in the system. For instance, the Chevrolet Silverado needs 60-65 psi for the fuel pressure to perform well. If the gauge reading is far from this, then the fuel pump could be the problem. A drop in pressure by 10% or greater normally indicates that the pump is degrading.
If the pressure gauge confirms a low reading, then inspect the fuel filter for blockages. A clogged fuel filter limits the amount of fuel flow that can pass through it and lowers fuel pressure. It is advisable to replace the filter after 30,000 miles because running on a clogged fuel filter reduces fuel pressure by 20-30%, according to the Automotive Maintenance Association. Using poor-quality fuel or running on low levels of fuel accelerates this problem.
Sometimes, the fuel strainer or suction filter inside the fuel pump may get clogged and prevent the proper drawing of fuel by the pump. These should be cleaned or replaced if damaged. A Consumer Reports test showed that 15% of all fuel pump failures are caused by clogged strainers, especially in older models where debris often settles at the bottom of the tank.
Also, check the fuel pump relay and wiring connections. A bad or corroded connection on the relay can reduce current to the pump and make it run less efficiently. According to Mark Bell, an automotive technician, corrosion in the fuel pump wiring can drop pressure up to 40% and affects the entire fuel delivery system. Faulty wiring can be fixed by repairing or replacing it.
If these fixes do not resolve the issue, the fuel pump itself might be failing. In a Toyota Camry, for example, a worn-out pump can lose up to 50% of its original efficiency, even if the rest of the system is intact. If this is the case, replacing the fuel pump may be necessary. High-quality replacement pumps, like those available at Fuel Pump, can restore the system to proper working condition and avoid costly repairs down the road.
Maintenance of the fuel system involves changing filters regularly, making sure blockages are checked, and replacing faulty parts to make the fuel pump last longer and ensure that the required pressure is provided to the engine.