What it does
The fuel pump is an electric pump inside the gas tank. It sends fuel up to the engine at the right pressure whenever the engine is running.
Common symptoms
- A whine from the gas tank that's louder than normal
- Long cranking before it starts
- Cranks fine but won't start
- Sputtering or surging at highway speed
- Losing power going uphill, towing or accelerating
- Stalling, especially when hot
What to look for
- Listen: on many vehicles, turning the key to on without starting runs the pump for a moment. Listen near the tank for a quiet hum. No hum points to the pump or its power supply.
- Fuse and relay: check the fuel pump fuse and relay before blaming the pump.
- Pressure test: the real test is a fuel pressure gauge on the engine, checked while cranking, at idle and after it warms up. A weak pump can pass a quick check and fail once it's hot.
- The simple one: make sure there's actually gas in the tank. Fuel gauges can be wrong.
Could be something else
A clogged fuel filter, a bad relay or a pressure regulator can act the same. A no-start can also be ignition or the anti-theft system not recognizing your key.
Is it safe to drive?
A failing fuel pump can quit without warning, including on the highway. Get it tested when the symptoms start. Fuel pumps are one of our specialties.
Related: Car won't start? · Bad ignition coil symptoms
Think it's your fuel pump? Northwoods tests and replaces fuel pumps right where your vehicle sits.