The fuel pump maintains pressure in the fuel lines so there is always a constant flow of fuel into the engine. This ensures that the injectors work correctly, and it also allows storage of fuel in a tank below and several feet from the engine. Without a fuel pump, your car simply wouldn't run properly. If the pump starts to fail, there are several warning signs to look out for.
The most common symptom of a fuel pump failure is a loss of power while driving. This occurs because there is less pressure in the fuel lines, and the engine is actually receiving less gas or intermittent streams of gas. This may happen while driving on the highway at high speeds, climbing up a hill or when you press the gas to drive away from a standing stop. A loss of power may also be attributed to faulty oxygen sensors or engine problems, but often it is the fuel pump, especially in older cars.
Another sign of a bad fuel pump is a misfiring engine which results in lurching car movements. This most often occurs when driving on the highway or at higher speeds above 50 miles per hour. The engine is actually lacking fuel so it is dying and then starting back up again. The drop in fuel pressure is the cause. Sometimes moisture and condensation will get into the tank, and cause a similar problem. Don't be fooled, however. More often than not, this is a sign the fuel pump is dying.
A no-start condition may be one of the most commonly confused symptoms of a failing fuel pump as many mechanics will tell you this could be due to the solenoid or spark plugs. However, it is often a sign the fuel pump is going bad. If your battery is charged and the car starter is firing (you hear the engine straining to start), but the engine does not turn over and start, it is probably due to a lack of fuel from the pump. To be certain, check your spark plugs and replace them if necessary. Then have the fuel pump inspected and replaced.
Pay special attention to the fuel pump if your car has stalled due to an empty gas tank. When the gas tank runs empty, it strains the pump and can cause it to fail. Always keep the car filled up and never try to drive on an empty tank.
