How to Test a Diesel Fuel Pump

A Diesel fuel pump is put together with automobile gas tanks and then they run on an electric motor from the car battery. While the fuel pump is working, it sends fuel to the fuel lines and then to the engine and this gives your car its own life once you ignite it. When a diesel fuel pump is not working properly, then your car lacks power and you end up not being able to start your car properly. Now, when this happens, there is a way to tell whether the cause of the start up malfunction is due to a bad diesel fuel pump or not by letting your diesel fuel pump undergo several testing. Thus if you want to test a diesel fuel pump, here are the steps on a DIY diesel fuel pump test.

Materials Needed:

  • Car manual
  • Spark plug tester
  • Pair of working gloves
  • Assistant
  • Socket wrench
  • Air filter kit

Step 1 - Locate The Car’s Spark Plugs

Your diesel fuel pump can be tested by assessing the spark plugs. To do this, open your car hood and locate the spark plug which is located somewhere near the battery or near the engine block. Moreover, the spark plugs are covered with plastic guards. Different car models have different placements of the spark plugs thus it is always wise to use the car manual to be able to locate the spark plugs properly. Before you touch the spark plugs, make sure that you wear insulated working gloves to protect yourself.

Step 2 - Use a Tester To Test The Spark Plug

Once you have located the spark plugs, attach one end of the spark plug tester to the power lead of the spark plug which is usually located atop the spark plug. The other end of the spark plug tester should be attached to the engine block in order to ground any current from the spark plug tester.

Step 3 - Start The Car To Fire The Spark Plug Tester

Once everything is connected, start the car and check if the spark plugs tester fires. To do this, ask a friend or a family member to start the car for you while you check that the spark plug tester fires. If it fires, then there is a possible problem in the car’s wiring and if it does not, then there are problems with the spark plug, so proceed to the next step; otherwise, check the wiring of the car.

Step  4 - Remove The Spark Plug

Use a wrench to remove the old spark plug and replace it with a new one. Once the spark plug has been replaced, start the car once more and see if you have problem starting it up. If you have problems starting up your car, then proceed to the next step, otherwise your diesel fuel pump is okay and you just need to replace a bad spark plug.

Step 5 - Clean The Air Filter

If the car still does not start properly, then the last thing that you should do before you conclude that the diesel fuel pump is not working well is to clean out the air filter which can affect the start up process of the car. If still your car does not properly start even if you have replaced the air filter, then chances are that your fuel pump needs to be replaced.