A clogged fuel pump makes the engine lose power significantly since the required amount of fuel needed at any instance for complete combustion is not supplied to it. Most vehicles run their fuel pumps at pressures of 40-60 psi, supplying fuel to the engine at a rate of about 1 to 2 quarts per minute, depending on the size of the engine and model of the vehicle. When the fuel pump becomes clogged with debris, dirt, or contaminants, its ability to maintain this pressure and flow is compromised. According to the ASA, up to 10% of vehicle power loss issues can be related to a clogged fuel pump.
When the fuel pump can no longer supply a consistent flow of fuel, the engine experiences fuel starvation. The situation occurs when the engine is not receiving appropriate quantities of fuel to keep up optimal performance. It manifests through a serious drop in power, particularly noticeable when the vehicle is accelerating. According to a report from Bosch Automotive, a minimal drop in fuel pressure can occur-say 5-10 psi below requirements-and still achieve a reduction of around 20 to 25 percent in engine performance. Examples include a 2015 Chevrolet Silverado, which needs approximately 50 psi at idle, and fluctuation far from this will make the engine run inefficiently.
If the fuel pump is clogged, engine misfire and hesitation may result. This is due to the fact that there will be no exact amount of fuel reaching the engine, leading to incomplete combustion. Most industry experts suggest that such power loss could be most noticed when the vehicle is under load, for instance, when accelerating on the highway uphill or when towing. The U.S. Department of Energy conducted a study and reported that, depending on the fuel delivery problem, fuel economy can take a hit as much as 10-15%, which would relate to problems caused by a clogged fuel pump.
It gets more acute in modern vehicles that use a precise delivery of fuel for fuel injection systems. Fuel injection requires just the right amount of fuel at the right pressure to maintain engine power. If the fuel pump is clogged, it cannot allow the correct volume of fuel to the fuel injectors, and thus poor performance and noticeably lower horsepower may be realized. A report by the Society of Automotive Engineers (SAE) noted that vehicles with direct injection engines are particularly vulnerable to power loss from a clogged fuel pump because the system demands higher pressure and more consistent fuel flow than traditional fuel systems.
As the fuel pump struggles to feed enough fuel, the ECU may make attempts to adjust the air-fuel mixture due to lack of fuel, but this can only go so far before severely affecting the performance of the engine. Ignoring a clogged fuel pump for a long period can damage other components of the engine, such as fuel injectors and the catalytic converter. In fact, a fuel pump that is left clogged can lead to total engine failure; repair costs range between $1,000 and $3,000, depending on the extent of the damage.
Conclusion A clogged fuel pump limits the fuel delivery to the engine, which can be characterized by fuel starvation, misfires, and a noticeable loss of power. Even a drop in fuel pressure by a few psi may result in major engine performance problems, including poor acceleration, hesitation, and decreased fuel efficiency. To know more about fuel pumps and their relationship with engine performance, log on to Fuel Pump.