How to Test If a Fuel Pump Is Working

Fuel pumps are built into most gas tanks and then run on an electric motor that draws power from the battery. While working, it sends the right amount of fuel through the fuel lines and into the engine. When it doesn't work you will notice a lack of power during peak performance, and slow or hesitating starts. But there is a way to check whether your engine problems are due to a bad fuel pump.

Things You'll Need

• Spark plug tester

Instructions

1. Open the hood of the car or truck and locate the spark plugs. They are located on the engine block and usually covered by a plastic guard.

2. Attach a spark plug tester to the spark plug power lead (located on top of the spark plug) and then attach the other spark plug tester lead to the engine block to ground it out.

3. Turn on the car and then start the car. If the spark plug tester fires, then you know that the problem does not exist in the wiring of the car. It may exist in the spark plugs, so go to step 4.

4. Remove the existing spark plug by using a socket wrench and simply turning the spark plug to the left, then replace with a new one fresh from the box. Start the car again and listen for the same type of hesitation that prompted you to check your fuel pump. If it is no longer there, the fuel pump is OK; the spark plugs just need to be replaced. If not, go to step 5.

5. Remove the air filter by uncapping the cover on the side of the engine and pulling the filter out. Clean it using an air filter cleaning kit. Remove all debris from the air intake. With fresh spark plugs installed, the engine should be firing perfectly. If not, your fuel pump is starting to wear down.

Tips & Warnings

• Replacing a fuel pump is a big job and will be expensive. Some extended warranties cover a fuel pump. Buy a single part extended warranty if you are worried about a bad fuel pump. It will save money and protect you from the steep costs of this repair.

References

• Test fuel pump
• Extended warranties
• Air filter cleaning kit