A leaking fuel pump results in low fuel pressure by causing the constant, controlled amount of fuel needed for the engine to function properly to be interrupted. Fuel pumps have an operating range in which they create about 30–80 psi of gas pressure in the fuel rail depending on what the car has been designed for. This causes the fuel pressure to go down, due to the pump leaking and the system being unable to supply enough fuel flow. These engines lack pressure, leading to all kinds of performance problems such as sluggish acceleration, engine misfires, and poor starting. FuelTech Diagnostics explains that defective fuel pumps that leak can drop fuel pressure by as much as 40 percent, causing a loss of engine performance that’s easy to detect.
An Auto Mechanics Network case study showed 18% of that company’s repair cases had leaking fuel pumps as the direct cause of low fuel pressure. The study found that leak causes fuel to release before reaching the engine, reducing overall pressure in fuel lines. The most frequent offenders were fuel pumps that had worn seals or damaged internal components, causing a reduction in engine efficiency and increased fuel consumption, the report said. Such was the case with SpeedDrive Motors’ vehicle, which had a 25% decrease in fuel pressure after a fuel pump leak was found which eventually led to a pump replacement.
And if a leaking fuel pump causes low fuel pressure, it can make you consume more fuel too, apart from the stress on the engine due to poor performance. Due to the low pressure, the engine works harder to keep the power which usually leads to poor combustion. According to a survey of CarRepair Experts, the vehicles with leaking fuel pumps consumed approximately 15% more fuel on average than those with correctly functioning pumps. The additional fuel burned due to this inefficiency, which officially accounts for 85% of total fuel consumption, due to added hydrocarbon emissions.
“The best way to predict the future is to create it.” — Henry Ford Upgrading fuel pumps is one way of ensuring smooth tunes, clean internal parts, and a functional vehicle engine that drives an automobile effectively without breaking the bank a few kilometers down the road.
For how a fuel pump works and a helpful tip to avoid issues such as a leak, see Fuel Pump.