A malfunctioning fuel pump would, in fact, lead to excess carbon buildup because of the improper delivery of fuel, which affects combustion. In such situations when a fuel pump fails or works inefficiently, it might result in running the engine a little rich due to more injection of fuel than what is burnt in the engine. This causes incomplete combustion, resulting in excessive carbon buildup on the combustion chamber and critical engine parts such as valves, piston rings, and injectors.
According to research by the Automotive Service Association, approximately 7% of vehicles on the road have carbon build-up problems related to poor fuel delivery, including those due to faulty fuel pumps. When too much fuel is introduced into the combustion chamber, the unburned fuel mixes with other by-products of combustion, such as carbon particles, and leads to the creation of carbon sludge or soot. This soot builds up over time, especially in high-mileage engines.
For example, if the fuel pump cannot provide the proper fuel pressure, which is usually 40-60 psi in most modern vehicles, this might lead to an over-rich air-fuel mixture. The rich mixture results in incomplete combustion, producing soot and carbon deposits. These deposits accumulate over time and clog up the intake valves and exhaust ports, further reducing the performance and efficiency of the engine. Severe cases can result in carbon buildup, causing misfires, rough idling, or even engine failure.
This is explicitly seen in the case of some vehicle models, such as the Ford F-150, whose faulty fuel pumps have been identified with carbon deposits that demean engine performance. Internal diagnostics by Ford showed that specific models had carbon build-up in the intake valves following long use with defective fuel pumps that caused an overly rich mixture.
Moreover, car professionals suggest that car owners also take periodic maintenance of the fuel system in order to minimize the possibility of carbon building up in engines. Over time, even slight problems with fuel pumps contribute to this issue. According to Bob Turner, a professional dealing with automobiles, “A minor malfunction in the fuel pump could be slight but may result in huge loss in engine performance over time due to carbon deposit build-up if left unattended.
If carbon build-up becomes extensive, it can lead to reduced fuel efficiency, knocking sounds, and engine stalling. As such, maintaining a well-functioning Fuel Pump is essential for preventing such issues. Regular fuel system maintenance, such as changing the fuel filter or cleaning the injectors, can help prevent over-fueling and ensure that the fuel pump continues to supply the correct amount of fuel to the engine.