How To: Fix a Clogged Fuel Injector

If you have a vehicle that has fuel injection, you may notice a decrease in performance and fuel mileage as your vehicle ages. This is due in part to fuel injectors becoming clogged with debris. Fuel injectors spray a fine mist of fuel, and if they become clogged, the spray can be diminished.

Clogged fuel injector

Follow these instructions and clean your fuel injectors.

Tools Needed

  • Screwdriver
  • Fuel injector cleaner
  1. Buy a fuel injector cleaner kit -- this will consist of a cleaning solution, a fuel pressure gauge, and a hose for connecting to the fuel injector. Make sure you are getting the right cleaner kit for your vehicle. The cleaning fluid may or may not come in the kit, so make sure that you have the entire kit before you start.
  2. Read your owner’s manual in order to locate the fuel injectors, the fuel pump and all of its components.
  3. Using your owner’s manual, disconnect the fuel injectors from the fuel pump. Connect the fuel return line or a U tube in order to get the fuel to return to the fuel tank during cleaning.
  4. Disconnect your pressure regulator.
  5. There will be instructions in your fuel cleaning kit on how to connect the cleaning kit to the fuel port. Use these instructions and attach the hose and the fitting to your fuel port. Because the cleaner is flammable, make sure that there is no exposure to fuel by the injectors.
  6. Take your gas cap off your fuel tank to eliminate pressure. When you clean the fuel injectors, there will be a big blast of pressure, so you want to give it a place to release in order to avoid combustion.
  7. Make sure that your fuel pump is turned off and then start your vehicle and let it run. It will take a few minutes for the cleaner to completely cycle through the fuel injectors. Check your kit instructions for specifics, but it can take up to 10 minutes for this to complete. Your vehicle will shut down when the cleaner is gone.
  8. Take the cleaner off of your vehicle.
  9. Reconnect the pressure regulator and fuel pump. Put your gas cap back on.

Start your engine and make sure that everything is working as it should be. Drive your vehicle and listen for noises or other things that would indicate that there is a problem. If you find that you have abnormal noises or that the cleaning did not help your fuel mileage, you may need to take your vehicle to a certified GM mechanic for more assistance. Remember to always replace parts with genuine GM parts to avoid premature wear or failure of other parts in the system.