Troubleshooting a Diesel Fuel Injector

closeup of a cracked fuel injector
  • 2-4 hours
  • Intermediate
  • 50-150
What You'll Need
A fuel injection pressure tester
Common screwdrivers and ratchets for your car

Here is an easy troubleshooting guide for your diesel fuel injector. For some of us, diagnosing and taking care of problems related to the fuel injector seems like too daunting of a task to complete on our own, so we take it to a mechanic. However, you could save yourself time and money if you follow this simple step by step guide to troubleshoot your fuel injector.

Testing Your Fuel Injection

Test your fuel injection pressure first. If the pressure is in excess of about 3,000psi, you may need to replace the injectors or have them reset. Then, inspect the tips of your fuel injectors’ nozzles. If the nozzles seem worn out or defective in any way, you’ll want to have them replaced. If everything is OK here, go on to a more detailed troubleshooting guide.

Checking Your Exhaust

Run your automobile for a few minutes. If you notice black smoke coming from the exhaust, your injectors may be leaking. Shut your automobile off and immediately inspect the area around your injectors. If there are leaks, assess whether or not you can fix them. If not, you’ll need to take it to a mechanic. If you notice blue smoke coming from your exhaust, a number of other problems may be apparent: low engine compression, worn piston rings, leaking valve seals or marked cylinder walls. These will need to be dealt with immediately.

Cleaning Your Fuel Injector

While running your automobile, if you notice a general decrease in power or acceleration, or if your engine idles in an unusual manner, you may want to clean your fuel injector. If this does not solve the issue, there may be a greater problem with your car than a fuel injector. Take it to a mechanic.

In following these steps, you’ll be much informed about your fuel injectors. An automobile is too great of an investment to just ignore its problems.