Some issues which concern pressure, fuel quality, and pump stress, do exist that can cause your Fuel Pump to fail after filling the tank. Fuel system is under high pressurization, so when the tank overfills, it could cause further problems to the Fuel Pump or the fuel lines. On some vehicles, a check valve to control system pressure is also used. A failed or clogged valve can create a wave of excessive fuel pressure from refueling that can damage a fuel pump or make the fuel pump intermittently turn off.
Fuel contamination is one of the most common causes of failure. Add low/mixed fuel quality, and during a refill, it can clog the fuel filter or damage internal components of the Fuel Pump. For example, water, dirt or debris in the fuel can clog the fuel injection system and pump, resulting in inadequate delivery of fuel and eventual breakdown. In 2020, AAA released a report stating that almost 15% of fuel-related breakdowns were due to contaminated fuel, something that usually won’t become evident until a tank is refilled.
A Potential Cause: Something Called vapor lock Which you get in older cars older fuel pumps. Vapor lock occurs when fuel vaporizes due to high heat or low pressure — a phenomenon that usually occurs when a vehicle is fueling or a short time after refueling. You would now not flow vapour which does not correctly permeate which makes trouble for the FUEL Pump to preserve the required strain. This is especially an issue with cars over 15 years or so, where things such as the fuel pump relay or fuel pressure regulator start to get in an age where, filling up a tank pushes air into the system, and causes the car to stall.
New age Fuel Pumps operate at very specific pressures, usually 30 to 80 PSI, depending on the vehicle. If the pump is already worn or damaged, the sudden water flow during fueling can be enough to push it beyond its threshold and result in complete failure of the fuel pump, or at least reduce its performance. In 2019, Ford was forced to recall nearly 1.4 million cars manufactured between 2010 and 2019 to replace defective fuel pumps that were found to fail, in some cases, immediately following fuel tank refills; Many consumers reported erratic fuel pressure readings following tank fill ups, according to a 2019 report from Automotive News.
So why does a Fuel Pump sometimes fail, specifically for newly refueled vehicles? With a full fuel tank, the fuel must be pumped at a higher flow rate through the pump, and this can push weak or compromised components past the point they should be able to handle or reveal deficiencies in the system that wouldn’t have presented themselves during normal operation. Fuel pumps that were already working under adverse conditions are more likely to fail after filling due to additional pressure and incoming fuel in the system.
Unfortunately, one causes of a Fuel Pump that leaves you with little, or no response after a fuel tank refill. These issues put pressure on the pump if it is already subject to failure. Fuel system problems can be avoided with regular maintenance and proper troubleshooting.