Q: After sitting without running for a long while, sometimes in-tank electric fuel pumps won't start.

asked by on

After sitting without running for a long while, sometimes in-tank electric fuel pumps won't start. That is the case with a Dodge Grand Caravan that I own, which sat without running since mid 2007. So my question is, how can a person make that fuel pump run again, without removing it from the tank? It's not like such fuel pumps were not designed to be submerged in fuel ... where there is NO OXYGEN to promote any rusting! Normally, when a person turns the ignition key to the run position, the electric fuel pump will run for a brief time (such as one or two seconds), then shut off. But I hear nothing from mine, and there is no fuel pressure, so the engine doesn't start, nor does the engine give any indication of trying to start when it's cranking ... and it does crank!

Check the power supply to the fuel pump, at the fuel pump terminals (as close as you can get) to be sure that the circuit actually functions. If there is power to the pump, but no operation, it is possible the fuel has oxidized, turned to varnish and other compounds, and basically glued the pump "shut". Also, it is not just a matter of air in the tank (oxidizing the fuel) but also moisture in the tank. Over so many years, the pump could be sitting in water simply due to accumulated water from condensation. If the tank has lots of water at the bottom, if it is a metal tank you might even need a new tank due to the possibility of internal corrosion. Although I suppose you could figure out a way to "unstick" a fuel pump that has sat in oxidizing fuel, and possibly water, for so many years, it is not worth it on account of safety and reliability considerations. If there is power and the pump doesn’t work, I would install a brand new pump and of course very carefully inspect the interior of the tank being mindful not to blow it up. Use a low power LED light...don’t use a 120 volt trouble light around fuel or, much worse, around fuel vapors. If you desire that the pump be replaced by a certified mechanic and the tank be inspected, simply request a fuel pump replacement. If you have additional concerns or questions, by all means please let us know.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. After sitting without running for a long while, sometimes in-tank electric fuel pumps won't start.

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.