Yes, a faulty Fuel Pump may indeed cause a rough engine idle. This problem normally is related to poor delivery of fuel to the engines. Most vehicles have an electronically controlled Fuel Pump equipped in them, which manages fuel at constant pressure under specified limits, such as between 40 to 60 psi for most petrol or gasoline engines. However, the Fuel Pump will slowly fail and may not maintain such pressures that are required during running. As a result, the engine may not receive a stable supply of fuel, causing the engine to sputter or idle roughly.
In fact, one study by the Automotive Research Association found that 25% of all rough idling issues reported in vehicles were linked to fuel delivery problems, which are often a direct result of a malfunctioning Fuel Pump. The wear and clogging of the internal elements can cause intermittent fuel delivery when the pump itself wears down or gets clogged. This erratic engine performance can be notably at idle, where speeds are low and air to fuel must balance delicately. When the fuel supplied to the combustion chamber isn’t consistent, the resulting malfunction may cause the engine to stall, misfire, or create problems in maintaining a correct, smooth idle.
A specific evidence is in the case of the Toyota Corolla 2015-2016 models. In this case, Consumer Reports cite a faulty Fuel Pump as the main cause of rough idling and stalling in about 4,000 vehicles in the U.S. The poor delivery of fuel caused unstable fuel performance, resulting in either low RPMs or actual stalling. In this case, the problem was traced to a faulty Fuel Pump that had difficulties maintaining the correct fuel pressure, causing the car to experience rough idling and not start easily.
Another possible culprit could be the fuel filter, as it often gets clogged when there is debris or some sort of contaminant in the fuel. If a fuel filter has clogging problems, it puts extra load on the Fuel Pump because it will have to work harder for the facilitation of fuel through it. The National Institute for Automotive Service Excellence (ASE) states that 40% of fuel delivery problems, such as rough idling, may be directly related to a clogged fuel filter impeding fuel flow. If a malfunctioning Fuel Pump is combined with a clogged fuel filter, the idle can become much rougher because the engine receives less fuel than it needs to run smoothly.
Sometimes, the electrical connections of the Fuel Pump can also be a reason for the rough idle. If the wiring or relay controlling the Fuel Pump is damaged or loose, it can prevent the pump from working properly, leading to a loss of consistent fuel pressure. This is often compounded by extreme conditions, either extremely hot or cold. Such was the case with Ford’s 2013 Ford F-150 trucks, in which faulty wiring in the Fuel Pump caused a loss of fuel pressure, leading to engine stall and rough idling at stoplights. This problem was so pervasive that Ford issued a recall for 50,000 vehicles.
As a Fuel Pump starts to fail, it affects the engine by causing an inconsistent engine performance that becomes more apparent at idle. The engine can surge, hesitate, or even stall if the fuel pressure fluctuates too much. But most problematically, for cars fitted with electronic fuel injection, since the Fuel Pump needs to supply the exact amount that the system demands. Any weakness in the performance will offset the air-fuel ratio, leading to an engine rough idle.
Rough idling is just one symptom of a malfunctioning Fuel Pump, but it is often a clear indication that fuel delivery is being compromised. Replacing a faulty Fuel Pump as soon as possible will help prevent further engine damage or stalling. Regular maintenance includes checking the fuel filter and inspecting the fuel system for any signs of damage or wear to prevent these issues before they impact your vehicle’s performance.
For a high-quality Fuel Pump replacement that ensures optimal fuel delivery and smooth engine operation, consider trusted suppliers like Kemso Fuel Pump for durable and efficient solutions.