The fuel filter is found along the fuel lines, either in the engine compartment or underneath the vehicle by the fuel tank. The job of the fuel filter is to trap any large foreign particles in the fuel and stop them from getting into the engine. With the force of the fast up-and-down motion of the pistons (which compress the air-fuel mixture so it will burn more efficiently), if any large particles manage to get in the fuel, this could cause some serious damage to the engine. So, maintaining a clean fuel filter is important to the performance of a vehicle’s engine. Every fuel filter is different and this is due to the differences in the fuel delivery systems. A carbureted engine (uses a vacuum to suck fuel into the engine) has quite a low-pressure fuel system. Fuel passes through fuel-resistant rubber hoses. So, the fuel filter is made of metal or plastic, with an inlet tube out one end and the outlet tube from the other, then a hose is attached over each end with a circular clamp. In vehicles with electronic fuel injection, the injectors will squirt fuel into each of the cylinders. Here fuel is highly pressurized by a pressure regulator. Because of the high-pressure system, the fuel lines have to be made of metal. Sometimes in these cases the fuel injected system is placed in a low-pressure section, and can be connected to the rubber hoses with clamp (almost like that in the carbureted system). However, the fuel filter is normally equipped with a threaded fitting on each end and it screws into the fuel lines on either side. .ads a:link {color: #0000ff;} .ads a:visited {color: #0000ff;}