How to Determine if a Car's Fuel Pump is Losing Pressure?
2 Answers
Methods to determine if a car's fuel pump is losing pressure include: 1. A "buzzing" abnormal noise coming from the fuel pump under the rear seat while the vehicle is in motion; 2. The vehicle experiences weak acceleration, especially with noticeable hesitation during sudden acceleration; 3. Difficulty starting the vehicle, including failure to start; 4. The engine warning light on the vehicle's instrument cluster remains constantly illuminated. As a fundamental component of the engine's fuel supply system, the fuel pump is responsible for drawing fuel from the tank during engine operation and delivering it continuously at a certain pressure through the fuel supply line to the engine. The high-pressure fuel pump then performs secondary pressurization, supplying a measured amount of fuel to each cylinder in accordance with the engine's firing order.
When my car keeps squeaking upon starting or suddenly stalls, I suspect it might be a fuel pump pressure leak. Fuel pump pressure leak means it can't maintain sufficient fuel pressure, causing the car to lack power when accelerating or shake severely at idle. Whenever I encounter this issue, I first check if starting the engine is difficult; if it takes several attempts to start when cold or jerks upon acceleration while driving, it's likely the problem. I also like to listen to the fuel pump sound after parking—normally, there's a steady hum, but if the sound is intermittent, the pressure might be insufficient. Of course, it's best to plug an OBD scanner into the car to check for error codes—if it shows low fuel pressure, repairs are needed immediately. I regularly change the oil filter because clogging can also affect the fuel pump's lifespan. These little tips have helped me avoid a lot of trouble.
