The Fuel Pump has to be checked for blockages in a step-by-step manner to ensure proper fuel delivery and engine performance. A normal Fuel Pump runs at 30 to 60 psi, depending on the model of the vehicle, while the optimal rate of fuel flow is 40-50 liters per hour. In cases of blockage, the output of the Fuel Pump may drop as much as 25%, and symptoms include sputtering of the engine or difficulty in starting the engine. The first step in inspection involves the use of a fuel pressure gauge for checking the fuel pressure. If, for instance, the recommended fuel pressure of a vehicle is 45 psi and the gauge reads 30 psi, then there could be a blockage affecting the efficiency of the Fuel Pump.
A blockage may be caused at any point in the fuel delivery system, either at the fuel filter, fuel lines, or at the Fuel Pump itself. Indeed, almost 30% of fuel-related engine problems start with clogged fuel filters, which are often partial blockages. The fuel filter should be replaced every 30,000 to 40,000 miles because a clogged filter can cut fuel flow by as much as 50%, significantly impacting throttle response and overall engine performance.
For blockages, disconnect the fuel line at the fuel rail or at the injector and observe the flow of fuel when the ignition is on. If there is no free flow, or if the fuel comes in pulses, then there is something wrong with the Fuel Pump or its associated fuel system. Also, the strainer inside the Fuel Pump assembly is a filter that industry experts recommend should be inspected as it builds up debris over time. If this strainer becomes clogged, fuel flow can be reduced up to 40%, resulting in severe engine performance problems.
The other diagnostic way is to listen to the Fuel Pump. A healthy Fuel Pump usually works very quietly. However, loud or whining noises most often mean that something inside has been seriously damaged or clogged, preventing its movement. According to the American Auto Repair Association, the cost of replacing a malfunctioning Fuel Pump may range from $200 to $1,000, depending on the car model; labor costs can be up to 60% of the total repair price.
Last but not least, superior diagnostic tools, such as the fuel system scanner, output in real-time the performance of a Fuel Pump and can track abnormalities like fluctuating fuel pressure. In a 2023 report, Consumer Reports claim that about 15 percent of all car breakdowns in the United States are due to fuel system failures, an included blocked Fuel Pump, underlined by the regularity in the inspection and maintenance involved.