A fuel filter sits between your car's fuel pump and fuel injectors. Essentially it helps screen out any impurities in the gasoline that your fuel pump may be sending toward your engine. By acting as a barrier and removing these contaminants, the fuel filter protects your fuel injectors, your engine health, and your car's overall performance.
Since you won't always be looking directly at your fuel filter, knowing the symptoms of a dirty filter can help you figure out the best way to fix your car or truck's problems. Replacing the fuel filter is an easy job, but you should first make sure that whatever trouble you're experiencing is indeed related to clogging in your filter.
1. Hesitating Engine
If your engine keeps hesitating when you press down on the gas, you probably have a dirty or clogged fuel filter. A clog means the flow of gas to the engine is restricted and this abnormal combustion ultimately reduces the car's power and responsiveness. If the car or truck doesn't respond when you accelerate or stumbles as it increases in speed, it could also be a sign of a dirty fuel filter.
Your engine needs a constant supply of fuel if it's going to run properly and efficiently. A fuel filter that has become dirty will constrict the flow of gas to the engine, so the vehicle supply is anything but constant. If the flow is excessively small, the car engine will stall. The more often this happens, the more likely it is that you rengine has a dirty fuel filter that needs to be replaced.
3. Not Starting
Since your engine requires a mixture of gas and air in order to fire up, it won't start at all if no gas is coming through. Failure to start is a definite sign of a dirty fuel filter or one that is completely clogged. It needs to be replaced before the vehicle will start properly.
Similarly, your car or truck not starting at all can also be related to a dead battery or a deteriorating ignition. If you've managed to rule those out, it's definitely time to consider the fuel filter may be the culprit.
4. Hard Starting
If your fuel filter is dirty but not completely clogged, you'll experience hard starting with your vehicle. It means that the supply of fuel to the engine is restricted so starting will become a lot more difficult. However, be aware that a dirty fuel filter isn't necessarily the only cause of hard starting in your car. The problem could also be in your plugs or your carburetor. Replacing the fuel filter would be a good first step toward diagnosing the problem.
5. Different Performance at Different Speeds
If you have a dirty fuel filter, the gasoline that reaches your engine will have impurities and your car won't perform as efficiently. This particular symptom can be hard to recognize at first, since it's quite possible that when pressing down hard on the gas pedal or cruising at highway speeds, you'll achieve good performance. Even with a dirty fuel filter, gas can still get to the engine properly if the pressure is high. At higher speeds, the fuel pressure would be providing ideal conditions for efficient motoring.
Since the engine demands more fuel at higher speed or loads, the engine will not perform as well if fuel filter is clogged. I may idle fine, but stumble or stall when accelerating or under load.