Most fuel filters contain a paper cartridge that removes sediments like dirt and rust from the fuel. They are located at the bottom of the tank on the fuel pump or in line with the fuel rail.
Proper fuel pressure is vital for engine operation and performance. Low fuel pressure results in a lack of horsepower, stalling, and a slow or no-start condition. A faulty fuel pump or a clogged fuel filter results in lower-than-normal fuel pressure at the rail.
Fuel injectors have small orifices that are easily clogged. Fuel filters save injectors from debris and are replaced at recommended intervals. Inline filters are fastened with clips or flare nuts at each end; the arrow on the case points in the direction of flow towards the engine.