How to Clean Fuel Injectors

Last Updated on January 16, 2019

The fuel injectors are the parts of the engine which are responsible for spraying a mist of mixed air and fuel into the intake valve of the engine from where the mixture goes into the piston cylinders for the combustion. The ECU (engine control unit) determines the amount of fuel which is pushed into the fuel injector.

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The fuel injectors need to be cleaned to get the peak performance from your engine. This peak performance results in the form of fuel economy, smooth running and low maintenance cost of the engine. The fuel injectors are clogged by the wax-like residue from fuel residue which is formed when engine is turned off and there is no fuel or gas to wash it away. This buildup of the residue may be small at the time, but the continuous buildup of this residue could cause major problems for the car’s engine and for you, in the future. The fuel injectors should be cleaned 15,000 to 30,000 miles and the cars with the higher mileages should be cleaned more often.

When a car starts to get lower mileages than it should or starts hesitating on hitting accelerator, it is a high indication that the fuel injectors of that car needs to be cleaned. The DIY (do it yourself) methods are very limited and things can get worse if you mess up reassembling the components so it’s not advisable. Therefore, a fuel injector cleaning kit along with a fuel line disconnect tool is necessary to clean your fuel injectors. The kit consists of a canister of fuel injector cleaner, a gauge to find out fuel pressure and a hose to attach to the fuel injector and the fuel rail.

Here is how to clean fuel injectors.

  • Study the engine layout of your car and go over its manual to find out the location of fuel injectors, fuel pump and its components.
  • Detach the fuel pump from the fuel injectors and connect the fuel return line while cleaning the injectors. A U tube will also do the trick. This is to make sure that fuel return to the fuel tank during the cleaning. See your car manual to find out how to do this.
  • Disconnect the vacuum line of the pressure regulator and attach the cleaning kit fuel pressure test port which is attached to the fuel rail in the engine. Your kit manual will provide detailed instructions on how to attach the fuel fitting and the hose to fuel port. The cleaners are flammable so be sure that there’s no fuel contact with the injectors.
  • Make sure to remove the fuel tank’s cap so that the risk of combustion due to the excessive built pressure is eliminated. This pressure could be caused by cleaner with the burst of pressurized cleaning solvent which is to inject a cleaning liquid into the fuel injectors.
  • Make sure that your fuel pump is turned off, start the engine and let it run. It will take from 5 to 10 minutes for the cleaners to cycle through the injectors and get used up. The engine will shut down on its own after they have been used up.
  • Remove the cleaner, reattach the fuel pump power supply, pressure regulator vacuum hose and put fuel tank’s cap back on.
  • Start the engine and make sure there are no abnormalities like a different noise and test the smooth run of the car by taking it for a drive.

If the vehicle still gives abnormal noises after following all the instructions, it’s time to go to a mechanic. Also, if your car is still giving lower mileage, hesitating or jerking, you should a mechanic immediately because this could be due to the fact that the fuel injectors need to be replaced or due to another problem.

Read also: Brake replacement costs


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