The first step in troubleshooting a low-pressure fuel pump is to confirm the pressure of the fuel using a fuel pressure gauge. The normal operating range for most vehicles is between 30 and 60 psi, although this could vary based on the model and make. For example, high-performance vehicles can require up to 80 psi for the optimal operation of the engine. If the fuel pressure is decidedly out of specification-that is, well outside-the pump or one or more of its components is at fault. In fact, says an Automotive Service Association report, one of the most telling signs of a faulty fuel pump is low fuel pressure.
Next, look at the fuel filter. More than 70 percent of problems with the fuel system originate with the fuel filter because dirt or other material may block the filter and inhibit the flow of fuel. If a fuel filter is clogged, this will force the fuel pump to work harder because it is forced to supply more pressure. The replacement of the filter is relatively simple and cheap, ranging from $20 to $60 for typical fuel filters depending on the model of your car.
Other important components to investigate include the fuel pump relay and the fuse. These are the electrical parts that govern how power flows to the pump. When either of them fails, the pump cannot produce the right pressure. You probably would not notice a defective fuse unless you actually looked at it. For instance, a blown fuse will not allow the fuel pump to get adequate power for the creation of appropriate pressure, thus allowing poor performance or a non-starting engine.
Also, check the fuel lines for any leaks or blockages. Leaking or clogged fuel lines decrease the amount of fuel supplied to the engine, hence causing low fuel pressure. According to the National Institute for Automotive Service Excellence, fuel line inspection should be part of routine maintenance to avoid such issues. In cases where the lines are damaged or obstructed, replacing them will restore proper pressure.
The fuel supply of the pump is another possible cause. If the electrical links that feed the pump are not good enough, or if the points are corroded, it results in a lack of persistent pressure by the fuel pump. According to the ETO, a multimeter would be used to test the voltage at the fuel pump; too low voltage could therefore be fixed by repair to the electrical connections or rewiring.
Finally, if these checks all return normal and the fuel pump still will not deliver the right pressure, then it might be time to replace the pump itself. Sometimes, especially if the pump has served beyond 100,000 miles, it could just have worn out or have been damaged. A failing fuel pump might fail to provide the required pressure, necessitating its replacement for the reinstatement of optimal performance in the engine.
Routine maintenance, like replacing the fuel filter every 30,000 miles, and a pressure check on the fuel pump will go a long way in preventing these issues. For anyone who has to deal with low pressure over a continued period, investing in a high-quality fuel pump, such as the ones by Kemso Fuel Pump, assures long-term reliability and performance.