How to Clean Fuel Injectors Without Removing Them

As the engine runs, over time, a lot of carbon builds up in the engine and fuel injectors causing you to burn more fuel and get bad fuel mileage. The fuel injectors can clog up, causing more gas usage. You should clean your fuel injectors every 30k miles. Cleaning your fuel injectors requires you to be a skilled mechanic because you have to take off your fuel injectors, clean them on a bench, and reinstall them. Luckily, you won’t have to go through those hassles at the end of this article because I will reveal how to clean fuel injectors without removing them.

how to clean fuel injectors yourself

How to Clean Fuel Injectors without Removing Them?

This is an easy-to-follow guide on how to clean fuel injectors at home without removing them.

Step 1. Get a fuel injector cleaning kit

Purchase a fuel injector cleaning tool suitable for your car’s make and model. You should get a cleaning tool that comes with a hose that connects to the fuel rail and fuel injectors and a canister of fuel injector cleaning solvent that can dissolve hard carbon buildups more effectively than other cleaning solvents.

Step 2. Locate the fuel rail

The fuel rail is an essential part of the fuel system. It feeds the fuel injectors with gas. The location of the fuel rails varies from car to car. Hence, you should visit your owner’s booklet to locate your fuel rail.

Step 3. Disconnect the fuel rail

The next thing you want to do is to go ahead and disconnect the fuel rail. Some fuel rails will require pressing down the clips to take them off. Some require loosening the clamps and holding them with a screwdriver to pull them off, while some require losing the bolt holding the fuel rail and a lead pipe from the gas tank. Whichever way your fuel rail is designed, disconnect it so you can connect the fuel injector cleaning kit later.

Step 4. Disconnect your fuel regulator pressure line (if your car has one)

Locate the pressure regulator and detach the vacuum line from it. Gently pull it out to take it off. Visit your owner’s booklet to know if your car has a pressure regulator. The regulator is usually located close to the injectors.

Step 5. Fill the fuel injector cleaning kit with a solvent

Take off the cover of the fuel injector cleaning kit and pour in the cleaning solvent. Ensure you fill the fuel cleaning kit to the brim.

Step 6. Hang the cleaning kit on the hood

You have to place the cleaning kit above the engine. You have to attach the cleaning kit to the hood. The cleaning kit has a hook that will allow you to attach it to the hood.

Step 7. Connect the kit outlet pipe to the fuel rail

Once you have successfully hanged the cleaning kit, you have to attach the kit outlet pipe to the disconnected fuel rail. The cleaning kit has many connectors, making it a lot easier to use on many cars, irrespective of the year, make, and model. Connect the sizeable connector and attach the cleaning solvent.

Step 8. Remove the fuel tank cover to prevent pressure buildup.

The cleaning kit will remove grime and debris by sending pressurized cleaning solvent into the fuel injectors. Ensure you take off the fuel tank cover before starting the cleaning. This will ensure there are no excess pressure buildups, which could cause combustion.

Step 9. Remove the fuel pump relay

Locate the fuse box and remove the fuel pump relay to shut off the fuel pump from sending gas to the engine. There are multiple relays in the fuse box, and they are of the same sizes and shapes. It is ideal for visiting the owner’s booklet to know the exact fuel pump relay.

Step 10. Connect the air compressor to the cleaning kit

Connect the air compressor to the cleaning kit – ensure you connect the compressor to the air intake connector of the fuel injector cleaning kit and set the PSI to 40, 45, or 50. You need pressurized air to export the cleaning solvent into the fuel rail.

Step 11. Start your car

Start your car and allow the engine to idle for some minutes until no more cleaning solvent is left in the cleaning kit. Once you notice the cleaning solvent is out of the cleaning kit, switch off your engine and disconnect the fuel injector cleaning kit.

Step 12. Reattach your fuel pump relay and fuel rail hose

Take off the cleaning kit fittings and hose from your fuel rail. Reinstall the fuel regulator vacuum hose and fuel pump lead hose. Cover the fuel tank.

Step 13. Start the car to ensure the fuel injector works

The engine should run smoothly after cleaning the fuel injectors, and the engine should have a normal sound. Start the engine to cross-check your work. Watch out for any leaking injector, vacuum leaks, or abnormal noise indicating an issue. Test the car within your neighborhood to make sure it runs nice and smooth. If you notice weird noise, you want to trace it or seek professional help. For a visual presentation, watch this.

You might want to know how to clean diesel fuel injectors without removing them; the above steps will work as well. However, there is a more straightforward method that works effectively, as the one above. Suppose you notice your diesel engine struggles to accelerate or stutter, or you see dark grey smoke coming from the exhaust tailpipe. In that case, it’s an indication your fuel injectors need some maintenance.

  • Get a diesel fuel additive that is compatible with your truck or car.
  • Turn off the engine and ensure your gas is below ¼.
  • Locate and open the truck fuel tank
  • Pour recommended amount of fuel additive into the gas tank.
  • Add more gas to the gas tank and run the engine for 10-15 minutes.

how to clean diesel fuel injectors without removing them


Can you add a fuel injector cleaner to a full gas tank?

It is not recommended to pour fuel injector cleaner into a full gas tank. Most cleaner manufacturers recommend adding the addictive in a nearly empty tank. However, while pouring fuel injector cleaner into a full gas tank might not affect your injectors negatively, to get optimum results, you have to pour the cleaner into a nearly empty tank.

How do you know if your fuel injector cleaner is clogged?

Clogged fuel injectors are usually caused by ineffective fuel filters allowing grime and debris into the fuel injectors. Clogged fuel injectors allow too little or too much fuel into the engine, causing several car engine problems. You can quickly tell when you have clogged fuel injectors by watching out for these signs.

  • Hard starting
  • Rough idling
  • Poor fuel economy
  • Difficult acceleration.

Can you clean fuel injectors yourself?

Cleaning fuel injectors require a mechanic to do so. However, there are simple and easy-to-understand guides that anyone can follow. Hence, this article. Ideally, anyone can clean fuel injectors using cleaning kits and sticking to instructions.

Do fuel injector cleaners work?

Do fuel injector cleaners work? Yes. Fuel injector cleaner is made of various cleaning solvents that can dissolve and clean hard carbon buildups and any grime and debris in the fuel lines.

How often do you need to replace fuel injectors?

Fuel injectors can last up to 50k to 100k miles. How long the fuel injectors last depends on how often you change your fuel filters and the type of gas you use.

Final word

If you’re still reading till this point, it implies you want to know how to clean fuel injectors without removing them. The easy way for any driver or car owner to maintain fuel injectors’ lifespan is to use fuel additives.  Some fuel-cleaning solvents do not just clean your fuel injectors; they clean your entire fuel system. A good example is seafoam. Hence, you want to know how to clean fuel injectors with seafoam – it requires pouring it into your gas tank just like every other fuel cleaner.

Osuagwu Solomon

Osuagwu Solomon is a certified mechanic with over a decade of experience in the mechanic garage, and he has over five years of experience in the writing industry. He started writing automotive articles to share his garage experience with car enthusiasts and armature mechanics. If he is not in the garage fixing challenging mechanical problems, he is writing automotive repair guides, buyer’s guides, and car and tools comparisons.

2 thoughts on “How to Clean Fuel Injectors Without Removing Them

  1. Hey Michael, sorry for the inconveniences. Did you check the fuel pressure coming from the pump?

  2. Hi got2007 kia Sorento 2.5 crdi auto ex 4×4. The engine everything been done new i even buy crank and cam sensor new but can not get any power or pulse on injectors and wire. Even put injectors directly onto main fuel line h/pressure pump but diesel not coming out properly spray nothing just some dripping at bottom out . Diagnostic been done show low pressure rail on bosch rail going to injectors. What can the problem be do i need to do injectors, ecu or pressure rail switch rail switch sensor solve issue. Please assist

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