The Beginner's Guide to Cleaning Fuel Injectors

Fuel injectors are the “small but mighty” players in your engine’s performance. As the name implies, they’re responsible for injecting fuel into the engine through a nozzle, which allows the gas to mix with air before it ignites. However, when injectors become clogged, it can keep your engine from running smoothly. Knowing how to clean fuel injectors and how to recognize when it’s time for a fuel injector replacement can prevent damage to your engine — and your wallet.

Fuel injectors can become clogged in a number of ways. The fumes and fuel within the engine can leave a residue on the nozzle, which eventually blocks it and affects the amount of fuel it is able to provide to the engine. It can also get clogged by small particles of debris in the gasoline or even from within the fuel system. For example, a corroding gas tank or corrosion within the lines of the fuel system can lead to small pieces of debris clogging the fuel injector.

When that happens, it delivers an inconsistent amount of fuel to the engine, which will affect how the engine idles and its performance overall.


What Are the Symptoms of a Clogged Fuel Injector?

There are a few different ways that your vehicle will tell you when you have fuel injector problems, so it’s important that you know what to look for. While some of these can also be signs of other problems under the hood, or may appear similar to a clogged catalytic converter, the most common indicators of a clogged fuel injector are:

‘Check Engine’ light comes on

If the fuel injector is clogged and not delivering enough fuel to the engine, or if it’s not firing at the right time, this light will start to glow.


Surges in the engine

If the fuel is being distributed unevenly, it can allow too much gasoline into the engine. That can cause the engine to suddenly surge, but it will then accelerate slowly and feel like it’s having a difficult time gaining speed.


Engine misfires

On the other hand, if your fuel injector isn’t providing enough fuel to the engine, there will be a delay when you hit the gas pedal.


Vibrating engine If the fuel injector is completely clogged and dead, it won’t fire, and that’s going to cause the engine to vibrate.


How to Clean a Clogged Fuel Injector

When a fuel injector is clogged, it needs a concentrated cleaning to resolve the problem. This can be done by a qualified mechanic, or if you know your way around the inside of an engine, you can do it yourself. To start, invest in a fuel injector cleaning kit. Make sure it is compatible with your vehicle; it should have everything needed to do the job.

Then follow these seven steps to clean a fuel injector:

1. Disconnect the fuel pump from the fuel injectors and remove the fuel injectors.

2. Disconnect the pressure regulator vacuum line if you have one.

3. Connect the cleaning kit to the fuel port, following the kit’s specific directions.

4. Remove your fuel tank cap to prevent pressure from building up.

5. Start your vehicle to send the cleaning fluid into your injectors and let it run until the kit is finished. (This may take about 10 minutes.)

6. Remove the cleaning kit, reattach your fuel pump and fuel injectors; put the fuel cap back on.

7. Turn on your car to see if it works properly. If you notice any “new” or unusual noises, contact your mechanic as soon as possible. If the engine seems to be running smoothly, go for a short drive to ensure it’s working properly.

In some cases, cleaning a clogged fuel injector might not be enough to salvage it. Your mechanic should be able to provide you with options when it’s fuel injector replacement time and can diagnose which fuel injectors are working properly and which ones need to be replaced.

Fuel injectors can cost several hundred dollars each, but your mechanic might be able to provide you with rebuilt or re-manufactured factory-quality injectors to help you save some money.


Other Fuel Injector Problems

In addition to clogged fuel injectors, leaking fuel injectors can create problems for your car as well. If your fuel injector is leaking, you have a different set of problems on your hands and need to look into fuel injector replacement or repair — immediately. Leaking fuel and vapors can cause an engine fire, which spreads quickly. Even if it doesn’t cause a fire, you’ll risk engine damage from the one-two punch of a lack of fuel and increased engine temperature. Taking care of it as soon as you identify the problem can prevent you from racking up some costly repair bills.

Warning signs of a leaking fuel injector include:

Smell. An injector that’s stuck open or is leaking will emit an odor of fuel.

Gasoline leak. If a fuel injector cracks or breaks, the fuel might leak out rather than flow through the nozzle. In these cases, you’ll be able to see gasoline on the nozzle as well as smell it.

Reduced fuel economy. When the fuel injector isn’t working, you’ll notice that you’re needing to fill up the tank more often.


Take Care of Fuel Injector Problems as They Occur

Whatever problem your fuel injectors are having, taking care of the situation in a timely fashion is the best thing for your wallet and for the life of your engine. Whether it’s time for fuel injector replacement or for cleaning or repair, you can keep your car running smoothly by making sure you’re addressing problems as soon as they arise.

Keeping your entire fuel system in great shape with regular automotive maintenance (check your owner’s manual for recommendations) and using a fuel injector cleaning additive recommended by the manufacturer can also help extend the life and performance of your fuel injectors. Check out our free e-book below for more ideas on how to extend the life of your car and save money! 




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