How to Clean Fuel Injectors

Injectors of both petrol and diesel engines get clogged over time. Recommended periodicity of cleaning is 40-60 thousand km. It can be done both at service or with your own hands. For cleaning dirty fuel injectors, there are means on sale intended for the professional and self-cleaning procedures. But even if your budget is limited, the car owners have invented some simple methods that allow performing cleaning of injectors on a high level with the help of improvised means in the garage conditions. Want to know how to flush fuel injectors? Then read our article and follow the instructions.

Ask clarifying questions or share your experience of cleaning you can in the comments.

What methods are used for cleaning fuel injectors

The professional method of cleaning fuel injectors on a special installation (cleaned with liquid and/ or ultrasound) is the highest quality, but also the most expensive. It allows coping with the most complicated impurities, however as a rule it is seldom required. Therefore, let's consider the most affordable and commonly used methods. Which of them you choose, you will decide based on your skills and capabilities.

Methods of how to clean fuel injectors at home:

  1. Use an additive poured into the fuel tank. This is the easiest and least effective method, it is used on a regular basis at intervals of 20 thousand km (very dirty injectors wash will not work).
  2. Feeding concentrated cleaner into the injector. Good efficiency, but requires certain skills in car maintenance. It can be done by two methods:
    • Feeding the cleaner from an aerosol can into an individual injector.
    • Feeding the injector cleaner into the fuel rail (used both with and without disassembly, but the methods differ in technical execution).

Cleaning the removed injector with a carburetor cleaner

To clean the injectors of the engine at home will allow such a means as «carburetor cleaner». This is a liquid in an aerosol can designed for cleaning parts of the fuel system. To work, the first way, you will need:

  • two pieces of clean rags, a knife and an awl;
  • a small insulated copper wire about one meter long;
  • plastic clamps (ties) and duct tape;
  • a 9-volt electric battery;
  • piece of gasoline-resistant hose 4-5 cm long;
  • a carburetor cleaner (at a choice, pay attention that the working cap of a cylinder on diameter has approached to the internal diameter of an oxygen hose and it could be inserted inside);
  • protective goggles and gloves (for personal protection).

Cleaning instructions:

  1. Remove the injector from the fuel manifold and use a rag to clean it from the outside (it is better to remove the rubber seals from it beforehand).
  2. Cut a piece of wire into equal parts and on one side of the resulting wires with a knife clean the insulation.
  3. Connect the stripped ends of wires to the battery with tape.
  4. On the opposite ends of the wires with an awl slightly expand the insulation for further connection to the injector.
  5. Make a hole in the cap of the carb cleaner with an awl in its upper part.
  6. Insert the cap into the rubber hose (the «native» hole of the cap will be plugged by the hose) and clamp them with a plastic clamp.
  7. To install the received adapter on the tank of carb cleaner.
  8. Cleaned from the outside injector connect to the adapter from the rubber hose and squeeze with a clamp.
  9. Connect the injector to the battery and you will hear a click, indicating that the injector is open.
  10. Put the adapter with the injector on a bottle of carburetor cleaner.
  11. Gently apply pressure (press).
  12. At the same time carburetor cleaner will come out in a vertical jet through the injector (this is what the glasses are for!).

Clean until the flare is even. After one cleaning you need to turn the injector upside down and repeat the operation. Then you can move on to cleaning the rest of the injectors.

If this method seemed complicated to you, the second way is much easier. You will need:

  • injector cleaner or carburetor cleaner (in a can);
  • the tube which can be inserted into the spray can (if such is not included with the remedy);
  • 5 cc syringe;
  • charger from an old, unwanted phone (5V);
  • a button with which it will be convenient to interrupt the power supply to the injector (you can do without it, but it is much more convenient);
  • сapacity (water bottle) where you can spray the liquid.

The algorithm of actions will be as follows:

  1. It is necessary to insert the test injector into the back of the syringe (as tightly as possible, with or without a rubber band).
  2. Insert the tube into the syringe spout (so that it enters very tightly).
  3. Prepare the charger wire for connection to the injector connector (you need to cut the connector and cut the wire lengthwise).
  4. Connect the injector terminals through the button to the charger (if there is no button, you need someone to plug and unplug the unit).
  5. Insert the tube into the atomizer of the cleaning agent, and turn the back of the injector into the prepared empty container.
  6. Press the atomizer so that a certain amount of liquid is in the syringe.
  7. Plug the charger unit into the socket and pulse the button to supply and interrupt power to the injector (do not supply power longer than 2 — 3 seconds, and if it is a low-resistance injector, even less).

If the injector is good, the detergent should come out under pressure from its back side. The blowing procedure must be repeated several times to achieve the desired degree of cleanliness.

How to clean fuel injectors without removal

You can clean without removing the injectors using a flushing cylinder, and as a cleaning composition, you will need to buy solvent (Vince, High Gear or other). For the work you will need:

Cleaning Dirty or Clogged Fuel Injectors — DIY Without Using Expensive Equipment

  • a clean two-liter plastic bottle with a tight screw cap;
  • car compressor (you will need to pump 3 atmospheres);
  • flushing fluid (about one liter);
  • drill and drill bit with a diameter of 13 mm;
  • two clamps (12-14 mm);
  • fuel filter;
  • two car nipples;
  • hose 12 mm in diameter and about one meter long.

The work algorithm is as follows:

  1. On both sides of the bottle (on the bottom and on the lid) drill a hole.
  2. In the bottom of the bottle to screw in a nipple with a screwed valve.
  3. Screw the nipple without the valve into the cap.
  4. Put the hose on the nipple, which is in the bottle cap and secure it with a clamp.
  5. To the second end of the hose connect the fuel filter and also secure it with a clamp.
  6. Start the car engine and warm it up to the temperature of coolant +90...+95 degrees.
  7. Turn off the engine and be sure to depressurize the fuel line.
  8. Disconnect the connector from the fuel line.
  9. Remove the hose of gasoline supply to the injectors.
  10. Put the above-mentioned fitting on the fuel pump from the previously assembled system.
  11. Pour the cleaning liquid into the bottle and close it well.
  12. Hang the bottle over the hood.
  13. Screw the compressor hose into the nipple at the bottom of the bottle (you can use a car booster pump).
  14. Inflate the bottle to a pressure of 3 atmospheres.

Fuel injector cleaning without expensive tools

After that, you should start the engine and let it idle for 15 minutes and rest for 15 minutes. Then start the engine again and let it run until the bottle runs out of cleaning fluid. When the engine stalls, you must gently bleed the pressure from the bottle! This can either be done with a nipple or simply by gently unscrewing the cap.

After that, you can disassemble the resulting system, connect the fuel hose back in place, and return the plug to its original position. After everything is assembled, you need to start the engine and let the car run for 5-10 minutes. It is extremely desirable to change the oil and plugs (especially the plugs) after performing the described procedure.

The method of cleaning is quite simple, but it has a significant disadvantage — no visual control of injectors condition. It may well be used for preventive purposes in case of suspicion that the injectors are clogged.


  • How do I know if my fuel injectors are clogged?

    The main signs are: the car doesn't start, there is an engine misfire, and idling is rough.

  • Can you clean fuel injectors yourself?

    Yes, it's possible to clean fuel injectors by yourself with a help of several instruments and special cleaning agents.

  • What is the cost of fuel injector flushing?

    Full injectors cleaning at a car repair shop will cost from 230 to 350 $. If you handle such cleaning on your own, you can spend only 15$ on injector cleaner.

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