It is true that a fuel pump relay can fail over time and present different kinds of performance problems with a vehicle. A fuel pump relay would normally last 10 to 15 years, but extreme heat exposure and electrical stress can accelerate wear. According to research from the Automotive Research Institute, approximately 30 percent of all relay failures are gradual, giving rise to intermittent fuel pump operation.
As the relay begins to fail, the voltage might not be sufficiently supplied to the fuel pump. For instance, if the relay is only working at 70% efficiency, the fuel pump might not be able to hold the pressure, as a range between 30 to 60 psi is required. This can eventually lead to serious underperformance and stalling pressure in a vehicle. As Bob O'Neill, a popular automotive expert, says, "Most of the time, a slow-declining relay is going to manifest itself as random stalls or difficulty starting, and that can be baffling for so many drivers."
One such incident was the driver who complained of intermittent start-up problems in his car. This was later found by a technician to be caused by the fuel pump relay, which had degraded below specs. Because of this gradual degradation of performance, the fuel delivery efficiency degraded up to 20%, affecting the engine's performance directly.
Failure of such a relay often masks its symptoms, sometimes acting out as a failing fuel pump or even problems in the ignition system. The National Highway Traffic Safety Administration estimated that nearly 15% of fuel-related failures are traced back to relay issues; hence, the importance of periodic vehicle maintenance and diagnostics.
Early detection will save time and money. Most relay problems can be spotted well in advance of a complete failure if the system is inspected every 20,000 to 30,000 miles. Performance should be monitored along with watchfulness for warning signals such as erratic starts or fluctuations in power.
Bottom line: A fuel pump relay can fail gradually over a period of time, causing severe performance problems in a vehicle. Check out Fuel Pump for more about keeping your fuel system in top condition.