To diagnose Fuel Pump contamination, you have to follow a series of diagnostic steps that ensure your fuel system is functioning correctly. Contamination in the fuel pump can lead to inefficiency, loss of power, and even total engine failure. A contaminated fuel pump usually occurs when particles, debris, or water enter the fuel tank and are drawn into the fuel system. This might occur either due to using low-quality fuel or poor servicing of the fuel tank. First, a check of the fuel filter should be carried out. Contaminants in the fuel system can easily be indicated from a clogged filter. A tinted fuel filter or restricted passage of fuel will serve as good indications of contamination. According to a study done by the National Institute for Automotive Service Excellence, ASE, 15-20% of fuel system problems are directly related to contamination of the filter. Check the filter for cleanliness, and replace it if it appears clogged.
Next, listen for unusual noises from the Fuel Pump. A fuel pump that’s contaminated will emit whining or grinding noises, which are symptoms of the pump fighting to operate due to contaminants blocking its mechanisms. According to the Car Care Council, a loud or inconsistent noise from the fuel pump may indicate that debris or rust is obstructing the fuel system, forcing the pump to work harder.
You can also test the quality of the fuel itself by looking for discoloration in the fuel lines. If the fuel appears cloudy or contains particles, it may have been contaminated with dirt, rust, or water. Water in fuel, for example, can freeze in colder temperatures, causing the pump to stop working altogether. Car manufacturers like Toyota recommend using fuel additives designed to remove water or contaminants when fuel contamination is suspected.
Additionally, testing of the fuel pump performance by the use of a fuel pressure gauge may help in identifying the fuel flow impeded due to contamination. In instances where the fuel pressure has dropped lower than usual readings, this could indicate foreign matter inside the fuel pump, impeding effective fuel delivery. According to industry experts, the fuel pressure is supposed to remain within a certain range, which usually varies between 30 to 50 psi for most cars, depending on the vehicle’s make and model.
For example, the 2020 Honda Civic had a problem with fuel pump contamination from poor-quality fuel, which caused engine misfires and stalling. The mechanics employed a diagnostic tool to check the fuel pressure and found that the Fuel Pump pressure was 15% lower than expected. After draining the tank and replacing the fuel filter, the issue was resolved, showing how critical it is to check for contaminants regularly.