When a Fuel Pump is clogged, it tends to exhibit certain symptoms that can be quite apparent and will certainly affect vehicle operation. The most common early sign is decreased fuel economy, as the pump tries to supply the correct pressure of fuel to the engine. Generally speaking, the pressure of a fuel pump on any vehicle can range anywhere from 30 to 80 psi. This pressure can drop drastically when it gets clogged, but efficient combustion depends on it, and this is one of the reasons why more fuel is consumed. As a product, drivers tend to see 10-20% less mileage as a result.
Another obvious sign of a clogged pump is engine sputtering. When this happens, the pump supplies fuel inconsistently which is especially noticeable in higher speeds. You might also like: Fuel pump fixes — What you need to knowFuel pump failure — How it affects the engine, why it’s the last considerationAccording to data from National Institute for Automotive Service Excellence (ASE), around 15% of engine performance complaints are associated with fuel pumps and most are reports of clogging due to debris or residual in the fuel system.
Hard starting is also a typical sign of this. A blocked Fuel Pump can prevent the flow of fuel to the injectors, making you crank longer or not starting up at all. Once the fuel delivery system becomes faulty it is common for mechanics to run into vehicles that have a significantly longer engine crank time and sometimes will take 10-15 seconds to actually start. Such a delay is often indicative of a blockage to the pump or very clogged fuel filter.
Another diagnostic way is to listen out for abnormal sound through the fuel tank. A healthy Fuel Pump usually works very silently, but once it gets clogged it starts making a whining or humming sound. These sounds are due to the pump motor straining against obstructions so that fuel can continue flowing. AAA reports that noise complaints are among the leading reasons drivers seek pump diagnostics at the gas station.
A definitive answer is given by checking fuel pressure with a gauge. Hook the gauge over the Schrader on the fuel rail and read pressure with engine running. It indicates a restriction in the system if the reading is well below manufacturer specifications. As an example, if a required pressure is 50 psi and the gauge only reads 20psi, then we can say that either the pump or filter is clogged.
We avoid this by using a high quality fuel and changing the fuel filter regularly. Change the fuel filter every 20K to 30,000 miles so that debris does not reach the pump. By investing in a good quality Fuel Pump and caring for it, the chances of clogging (and all that follows) decrease dramatically – leading to stable engine performance and a longer pump service life.