Yes, a faulty Fuel Pump can indeed cause hard starts by disrupting the fuel flow to the engine. The Fuel Pump is designed to provide fuel at a certain pressure, generally between 30 and 80 psi depending on the application design. If this pressure cannot be maintained by the pump, then there will not be enough fuel supplied to the engine for proper starting, thus resulting in prolonged cranking or failure to start altogether. Sometimes, a malfunctioning or dying Fuel Pump might allow fuel pressure to drop well below what is needed for the engine’s correct firing.
Fuel Pump failure can be brought on by numerous causes: wear and tear, electrical malfunctions, or blockage of the fuel filter. For example, a clogged filter would minimize fuel flow, tending to make the pump work harder, which in turn reduces its capacity to provide adequate fuel pressure. Replacing the fuel filter every 30,000 to 50,000 miles can help avoid this problem, as a clean filter ensures smooth fuel flow. Indeed, clogged filters have been known to cut fuel flow by as much as 30% and directly impact the performance of the pump in the process, contributing to hard starting conditions.
Another common cause of hard starts related to the Fuel Pump is a failing fuel pump relay. This relay controls how much electrical current is passed on to the pump. Sometimes, this relay may not work right, which will affect the amount of power that reaches the pump. Eventually, quality and continuity of fuel delivery may weaken or happen periodically. Thus, the investment in replacement of a bad relay ranges usually between $20 and $50 compared to the cost of a Fuel Pump, which could be well in the range of $400 to $800.
In 2019 alone, a number of automobile brands such as Toyota and Subaru recalled cars due to faulty Fuel Pumps, with defects causing problems like hard starts and stalling engines. These were tracked down to a faulty part on the Fuel Pump that was unable to support proper fuel pressure. This also speaks to the lesser-known point above-the importance of an effective pump in achieving surefire engine starts.
As Henry Ford once said, “Quality means doing it right when no one is looking.” Maintenance of the Fuel Pump and other related components like the filter and relay remains very important to avoid hard starts that may hinder smooth performance of the engine.
For further detail about how to maintain the Fuel Pump and solve the problems related to hard start, please refer to Fuel Pump.