Can You Start a Vehicle With a Bad Fuel Pump?

Reading Time: 3 minutes

The electric fuel pumps fitted to modern cars, pickup trucks and SUVs are designed and engineered to provide tens of thousands of miles of trouble-free motoring, but they are mechanical devices that wear out over time and they can and do fail. When a fuel pump stops working, the engine will turn over but it will not start. This is because the car is essentially out of gas. There may be fuel in the tank, but it is not getting to the engine.

There is really no way around this problem unless the lines feeding fuel from the gas tank to the fuel filter and from the fuel pump to the engine are connected instead to some sort of auxiliary pumping device, but this is a stop-gap solution at best and a new fuel pump will still be needed. To avoid such situations, drivers should check their fuel pressures regularly and watch out for a few tell-tale warning signs.

Signs of a Bad Fuel Pump

Knowing how to tell if fuel pump is bad can be extremely valuable information. Identifying the fuel pump as the source of starting and running woes avoids money being spent on unnecessary repairs, and replacing a worn out fuel pump before it fails completely can prevent nerve-wracking breakdowns and their associated costs. The most common signs that suggest a fuel pump may be reaching the end of its road include:

High-speed stuttering

  • High-speed stuttering: Cars with failing fuel pumps sometimes stutter when being driven at a consistent speed. This is a sign that the engine’s fuel supply is being temporarily interrupted, which normally indicates that the fuel pump is finding it increasingly difficult to do its job.

Sudden surges

  • Sudden surges: An engine that surges for no reason is one of the most common bad fuel pump symptoms. When this happens, drivers often think that the gas pedal is stuck. It is usually caused by a faulty fuel pump motor.

Having trouble getting up a hill

  • Having trouble getting up a hill: Fuel pumps work harder when engines work harder, and cars that lose power when their motors are stressed often have fuel pumps that are nearing the end of their useful lives.

Soaring temperatures

  • Soaring temperatures: Overheating followed by an engine stall is often a sign that fuel pump failure may be imminent. If restarting the vehicle leads to another stall, the fuel pump is the most likely culprit.

Plunging gas mileage

  • Plunging gas mileage: A sudden drop in gas mileage is one of the most overlooked bad fuel pump symptoms. Falling mpg is often put down to poor tuning or a general state of disrepair, but it is frequently caused by fuel pumps with relief valves that are no longer working properly. If these valves do not open when they are supposed to, too much fuel flows into the engine and gas mileage suffers.

Get a Fuel Pressure Gauge

Drivers who do not know how to tell if fuel pump is bad or do not want to watch out for signs of a bad fuel pump can put their minds at ease by getting, and regularly using, a fuel pressure gauge. This device will tell them when it is time to replace the fuel pump. While the devices are universal, the location of the ports that they plug into are not. Before using a fuel pressure gauge, the owner’s manual should be consulted for the port location, the recommended fuel pressure and the testing procedure.

The gas pedal must be pressed when checking fuel pressure, which is why using a fuel pressure gauge is usually a two-person job. The gauge should be watched when the engine is revved, and the reading should then be checked against the figures in the owner’s manual. Using a fuel pressure gauge once a month can give vehicle owners advance warning of fuel delivery problems and allow them to replace their fuel pumps before they fail.