Troubleshooting an Electric Fuel Pump

While electric fuel pumps tend to be much more secure and long lasting than their standard counterparts, it's nonetheless inevitable that an electric fuel pump will break down or experience troubles after a certain amount of operating time. The fuel pump may become obstructed, thereby losing its ability to pump fuel into the engine system. It may become inefficient, and use up too much fuel or not be able to deliver fuel at a good rate. Whatever the problem that develops, if you have a basic knowledge of electrical circuits and a bit of time, you can work to troubleshoot and fix the fuel pump problem.

Tools and Materials

  • Jumper wire (one segment that is two to three inches long, two segments that are about 3 feet long)
  • Tester light
  • Vehicle owner's manual

Listen for Trouble

One of the best ways to identify a problem with the fuel pump is by listening to the pump action itself. Open up the fuel filler cap where you'll pump fuel into your vehicle and ask for a friend or assistant to turn on the ignition of the car. Listen for a deep rattling sound or any other unusual noise coming from inside of the fuel tank. If you do notice something, the problem may not be electrical and you should plan to take your vehicle in to the mechanic.

Check Out the Fuse

One of the most common electrical problems with a fuel pump circuit is a blown fuse. Fuses can be blown quite easily, and a blown fuse will make it so that you cannot operate the fuel pump as you'd like to be able to. Open up the dashboard panel beneath the steering wheel of your vehicle and identify the fuel pump circuit with the help of your owner's manual. Check to see if the fuse is blown and replace it if necessary.

Look to the Connecting Pieces

The problem may also be with the connecting pieces in the fuel pump system. Examine the fuel pump hoses and connecting lines to make sure that there are no obstructions or breaks anywhere.

Look to the Relay

The fuel pump relay is responsible for delivering the electric charge to the system itself. Remove the fuel pump relay with the help of your vehicle owner's manual (most relays are located under the dashboard). Test the ignition again and use a testing light to see if the fuel pump relay system is receiving an electrical impulse from the battery. You may need to replace this system if the electrical signal is not activating properly. If there is no signal, use the jumper cable to apply voltage from the battery directly to the fuel pump. Ignite the engine again and listen for fuel pump activation. If the fuel pump turns on properly, replace the relay and test the system once again.

If these methods do not work, take your vehicle in to a mechanic for further inspection.