The main reason for fuel pump blockage is the dirt, rust and the sediment particles that form in it because of the contaminants settling in your fuel tank. The particles sometimes come into the fuel system from poor quality gas or particles that are formed as a function of age. Minor contamination can introduce numerous problems; for example, a study has shown that as little as a 10-micron particle can clog a fuel filter and reduce the flow through the filter, eventually making it to the pump where it makes life difficult. Blockages impede the efficiency of the pump and, with severe cases, can overheat it as it struggles to push fuel through a restricted system.
Fuel pump blockages can be caused by water contamination. Due to condensation, there can be water in the fuel tank (in more humid or cold destinations) which mixes with the fuel. Eventually this moisture will corrode, producing rust particles that further clog the pump and filters. Water contamination can lead to a twenty-percent decrease in fuel-burning efficiency, preventing full combustion and causing the engine control module (ECM) to correct its behavior so that it does not start as often or run as smoothly.
Low-fueling of the fuel tank can also lead to blockage. As fuel levels get low, the sediment and debris usually pools near the bottom of the tank. These contaminants could potentially clog the intake screen or filter over time when the fuel is drawn in as the pump pulls fuel. The water stress binge places added pressure on the pump, cutting by 30,000 miles of its assumed 100,000-mile life-span if the container is commonly near vacant.
Fuel FiltersBefore they make it to the pump, particles have to be netted by the fuel filter as well. Replacing the fuel filter every 30000 miles--or often as needed in lower-mileage use--can do a lot to keep contaminants from reaching the pump. However, failure to maintain the filter and will also cause a blockage in the pump downstream of the restriction due to self-entanglement.
In the words of Carroll Shelby, "The cleaner your machine, the longer it will run. Regular fuel filter changes and high-quality fuel can help reduce the chances of blockages, which will in turn extend the life of important parts like the Fuel Pump. Cleaning up any potential contaminants will help drivers maintain the efficient operation of their fuel systems and prevent expensive repairs that come with a clogged fuel pump.