Testing a Fuel Pump properly requires several tools for performance measurement, which will ensure whether the pump is delivering fuel at the correct pressure. The main tool one needs is the fuel pressure gauge, which is used to measure fuel pressure in the fuel line. Depending on the brand and model, most the newer vehicles require a range between 30 to 80 psi. If the pressure drops outside of the recommended range set by the manufacturer, this will show that the Fuel Pump is weak or in failure. A good-quality fuel pressure gauge will cost anywhere from $30 to $70.
Another important tool is a multimeter, which is utilized in testing the electrical current flowing to the Fuel Pump. The multimeter checks for voltage at the pump’s electrical connectors, which by inference means that it will check whether the Fuel Pump is getting the appropriate amount of power required for its normal operation, normally in a range of 12 to 14 volts. And more often than not, because of some electrical problem, the pump does not get that much power and hence exhibits poor performance. Multimeters are fairly versatile tools and usually vary from about $20 to $100, depending on the features and accuracy.
A scan tool or an OBD-II scanner comes in handy for any advanced diagnoses that could very well hint at engine codes relative to fuel delivery problems. The weak Fuel Pump would thus set off diagnostic trouble codes-for instance, P0087, pointing to low fuel pressure that pins such a problem. OBD-II scanners run anywhere from 50 to 200 dollars, though the more advanced models show very detailed data regarding fuel system performance.
Another helpful tool is a fuel pump relay tester; it is all the more important when attempting to troubleshoot intermittent Fuel Pump faults. The relay limits electrical feed to the Fuel Pump, and when the pump works erratically-or just fails to work at all-it might as well be due to a faulty relay. This tool comes in handy in testing the relay for correct functioning, which should give continuous power to the Fuel Pump. Relay testers are affordable and are in the range of 15-40 dollars.
For safety, it is a good idea to have protective gloves and safety glasses around when working with fuel systems; fuel is hazardous. Secondly, a shop manual specific for your vehicle is required for referencing proper testing procedures and specs for Fuel Pump pressure.
There have even been reported cases of pervasive fuel pump failure in 2020 that forced major automakers like Toyota and Subaru to issue recalls. A lot of costly repairs and performance issues could have been saved if the proper testing tools were applied to detect such failures well in advance.
As the great Benjamin Franklin has always said, “An investment in knowledge pays the best interest.” The right kind of tool for testing Fuel Pumps saves not only time but also money, besides ensuring that the vehicle runs safely and efficiently.
For more information on testing and maintaining Fuel Pumps, refer to Fuel Pump.