How to Clean Fuel Injectors at Home

Diesel injectors are the heart of your engine's fuel system. However, as we discussed in a previous blog, diesel fuel injectors are prone to fuel contamination failure. If you’re starting to see symptoms of reduced power, worse milage, rough idling or even hard starts and want a cost-effective way to maintain your injectors, you’re in the right place. Below is a complete DIY guide to cleaning your diesel fuel injectors at home using basic tools and affordable supplies.

What You Need to Clean Fuel Injectors:

• Tire Valve or Plastic Tube/Straw
• Solvent Spray (e.g. carburetor or brake parts cleaner) 
• Injector core removal tool 
• 9V to 12V battery
• Alligator clips and wires
• Degreaser
• Small Brush
• Electrical tape

Step-by-Step Guide to Cleaning Fuel Injectors:

#1 Remove O-Rings and Pintle Caps

Start by carefully removing any o-rings and pintle caps from the injector. These small rubber and plastic components can get damaged easily, so use gentle pressure. If you plan on reusing the o-ring or pintle cap, be careful not to damage it when removing, however we recommended replacing it.

#2 Use a Tire Valve or Straw

To make the cleaning process easier, we recommend using a tire valve stem (a small plastic hose can also work) in order to connect your solvent spray to the injector.  Remove the core with a core removal tool so the solvent can flow freely. Removing the core is not necessary though recommended for the best results. 

 #3 Use a Solvent to Clean the Interior

To clean the injector you’ll need a solvent which can be purchased at your local hardware or repair store. We recommend using a brake parts cleaner or carburetor cleaner. Our favorite cleaner is the Royal Purple Max-Clean Fuel System Cleaner and Stabilizer which can be purchased at most hardware stores or through Amazon. Any solutions that contain polyetheramine (PEA) are preferred as they are most effective when dissolving thick carbon residue. 

Once the core has been removed, wrap the straw for the solvent in electrical tape until it fits snug in the tire valve stem. Next put the injector into the valve stem. After, put the straw back in the solvent can. 

#4 Activate the Injector With a Battery

Fuel injectors open only when powered.  You will need to activate the fuel injector in order to spray a solution. To mimic that action, use a 9V or 12V battery. Grab a few alligator clips and attach them to the leads on the battery. Now attach the other ends of the leads to the ports on the side of the fuel injector. This will automatically turn the injector on. 

#5 Clean / Flush the Injector

Once the straw is connected into the opening of the fuel injector, it’s time to start spraying your solution inside. Hold the spray down and repeatedly tap one of the battery ports for about 60 seconds. Doing this will flush the fuel injector out and remove all of the residue stuck inside. 

When finished take the alligator clips off of the injector, peel off the electrical clip and remove the straw. Let the injector air dry.  

#6 Use a Degreaser and Brush for the Exterior 

Finish by cleaning the outside of the injector. You can spray the outside of the fuel injector with a degreaser and gently scrub the exterior with a brush to remove any surface grime. If you’re using the same o-rings you can dip them in gasoline to keep them from corroding. 

If needed, repeat this process for all of your injectors. 

And just like that, your injectors are ready to be installed again! We recommended cleaning your fuel injectors about once a year. View our selection of diesel fuel injectors. 

The information provided in this article is for general guidance only. Always refer to your machine’s manual or consult a qualified mechanic before performing any maintenance or repairs.