Yes, a faulty fuel pump can cause an engine to misfire. This is pretty common, especially for older models or those whose fuel pumps are worn out. The fuel pump is a very important component in supplying fuel from the tank to the engine at the required pressure. Most vehicles need a fuel pressure in the range of 35-70 psi for the proper functioning of the engine. If the fuel pump does not maintain proper fuel pressure, then the engine would not get sufficient fuel for proper combustion, which often causes misfires.
Research from the Automotive Repair industry indicates that about 10-15% of all engine misfires in modern vehicles can be directly related to fuel delivery problems caused by a faulty fuel pump. For example, a car that experiences engine misfires under load, such as during acceleration or at high speeds, often indicates an issue with the fuel pump’s ability to provide a steady flow of fuel. A misfire occurs when one or more cylinders fail to ignite properly, which can be caused by insufficient fuel, improper fuel mixture, or spark issues.
In 2017, Ford recalled over 400,000 vehicles for a faulty fuel pump that might cause engine misfires and stalling; indeed, when the fuel pump failed, problems with the ignition system surfaced. Several reports of vehicles stalling on highways prompted the recall because it was believed that such instances may lead to engine misfires, thus creating dangerous driving conditions. An insufficient fuel pump, in an erratic manner, supplies the engine with too little fuel for a lean mixture or too much for a rich one, resulting in misfiring and a rough engine.
Aside from a faulty fuel pump, lousy fuel will make it worse. Impurities, dirt, or even water within the fuel may block its filter and, in a worst case, damage internal parts within the pump. According to a 2015 study by the Car Care Professionals, fuel contamination was responsible for over 18% of the fuel pump-related engine misfires. These studies indicated that the vehicles running on low-quality gasoline had more incidence of misfires as contaminants resulted in the failure of fuel pumps, which consequently caused misfires and rough idling.
Most fuel pumps last for 100,000 to 150,000 miles, but this number can vary based on a number of variables including driving habits and fuel quality. A worn-out fuel pump might not be able to support the proper pressure required, which can cause a misfire condition. On average, it costs around $400 to $600 to replace a fuel pump. This depends on the model of the car and the cost of labor. Still, some owners try not to replace the fuel pump, although running the engine for more time with misfires might cause additional damage.
The dependence of fuel pumps on engine misfires has been studied over time. The fuel pressure will give an indication of a faulty fuel pump, and in most cases, if the pressure drops, that is an indication of a fuel pump malfunction. Industry expert John K. Armstrong adds, “Fuel system problems, especially fuel pump failures, are one of the major causes of misfires, especially in high-mileage vehicles.” The results here emphasize the need for periodic maintenance and fuel system checks for the right functionality of the fuel pump to avoid misfire in the engine.
In the end, a bad fuel pump can indeed cause engine misfires by supplying inconsistent fuel to the engine. Regular maintenance and timely diagnosis of fuel pump issues are critical in preventing these types of engine performance problems. If you experience misfires, particularly during acceleration or under load, it’s essential to inspect the Fuel Pump and address the issue promptly to avoid further complications.