How Often Should I Use Fuel Injector Cleaner?

how often should i use a fuel injector cleaner

How Often Should I Use Fuel Injector Cleaner?

How often you use a fuel injector cleaner will depend on the quality of the fuel that you use, and how often you drive. However, it seems that there isn’t a set guideline that dictates how often you should use one.

Some mechanics suggest once every 12,000 – 15,000 miles before an oil change and some manufacturers will recommend every 3000-5000 miles. Some manufacturers and mechanics also suggest cleaning your fuel injection system if your vehicle has been sitting for a few months.

What is a fuel injector cleaner?

A fuel injector cleaner is an additive that cleans the carbon buildup, other by-products, and deposits, such as water and octane-boosting ingredients that can clog your vehicle’s fuel injection system and accumulate in the bottom of your fuel tank, in the fuel line, in the combustion chamber, the fuel pressure regulator, and behind the intake manifold valve.

There are various well-known manufacturers that produce fuel injection cleaners that do a great job at cleaning the carbon buildup found in a dirty fuel injector, and they’re super easy to use yourself. As an example, Liqui Moly has Liqui Moly 2007 Jectron Gasoline Fuel Injection Cleaner that receives excellent reviews, and consumers report that they notice a difference in how well their vehicle runs after using it.

Lucas also produces a fuel injection cleaner that at the time of publishing this article, had over 3300 reviews with a very high rating. The great thing about this fuel injector cleaner is that it works for both gasoline and diesel engines and does not contain alcohol, solvents, kerosene, or diesel fuel.

2 Reasons Why Additives Build Up

There are 2 primary sources of build-up, ethanol, and carbon.


Carbon is the main concern when it comes to cleaning your fuel injector. Because fuel doesn’t completely combust during the combustion process, carbon deposits are left behind. Keep in mind that carbon is actually the fuel that is leftover because engines don’t burn 100% of the fuel. These deposits can end up in the exhaust system and fuel injection system, including the fuel injectors, and combustion chamber leading to problems with system performance.


Ethanol was originally introduced to start reducing carbon monoxide emissions from vehicles but these days, vehicle engines don’t need ethanol to lower fuel emissions, but, it’s still used as a filler to lower the cost of gasoline. This isn’t a problem for more modern cars but older cars have a problem with it. Because ethanol is alcohol, it’s corrosive which means it can be very hard on vehicle parts. It can cause carbon deposits to dislodge and move throughout the engine causing problems. It also oxidizes and emulsifies to form other by-products which cause buildup throughout the fuel injection system, including the intake manifold valve.

5 Benefits Of Using A Fuel Injector Cleaner?

5 benefits of using a fuel cleaner are:

  1. Clean the fuel injector system, removing carbon buildup and other debris
  2. Improve gas mileage and provide better fuel economy (If you’re interested in knowing what fuel economy to expect from your vehicle, check out
  3. Help prevent your fuel injection system from getting clogged up
  4. Improve overall engine performance
  5. A smoother running, more powerful feeling engine
  6. Reduced spending on fuel
  7. Reduce emissions

3 Signs That You Should Use A Fuel Injector Cleaner

There are a few signs that you need to clean your fuel injector:

  1. Engine stutter, hesitation, or misfire could indicate a clogged injector
  2. A decrease in fuel efficiency (lower gas mileage than you typically get)
  3. Difficulty starting or rough idling could also indicate that you have a clogged fuel injector

How Does A Fuel Injector Cleaner Work?

According to, in addition to solvents and other components, one of the main ingredients in a fuel injector cleaner is a chemical called polyetheramine, also referred to as PEA for short. “It’s really the only one – for carbonaceous deposits – that’s effective for the environment we’re using it in,” Richardson said.

Richardson says a fuel injector cleaner can be thought of as an oven cleaner or laundry soap. “These fuel detergents get down in the deposits,” said Richardson, breaking them into “very small particulates” that pass through the engine’s exhaust system.

Put another way Barker said, “PEA detergents fully solubilize deposits so they can easily be washed away and burned through the normal combustion process in the engine.” But that’s not all. He also noted, “Due to the surface-active nature of PEA detergents, they are also more effective in preventing the formation of additional deposits than other types of fuel-additive detergents.”

Why does a fuel injection system stop working?

Here are 3 common reasons a fuel injection system fails:

1. Dirty or Clogged

Over time the injector nozzles can become dirty and either partially or fully clogged. Leftover carbons from the fuel can cause build-up and block the injector.

2. Leaking Externally Or Internally

If there’s a break or a crack, the injector will leak.

3. From A Mechanical Failure

Normal wear and tear or lack of regular maintenance can cause a mechanical failure such as the o-ring becoming damaged.

3 Things To Consider Before Buying a Fuel Injector Cleaner

When choosing a fuel cleaner, consider these 3 things:

  1. Refer to your owner’s manual to ensure the manufacturer doesn’t recommend a particular type.
  2. There are also special high-mileage cleaners available that might help.
  3. Look for a fuel injection cleaner that contains PEA because it is the strongest cleaning agent and does the best job at removing carbon and other residue. Some cleaning agents have PIB or PIBA but neither one works as well as PEA.

How To Use A fuel injector cleaner

It’s simple to use a fuel injector cleaner.

When you have gas in your tank, and preferably a full tank, add the cleaner, according to the manufacturer’s instructions, and let it run through your fuel injection system with the gas.

Most vehicle owners notice an improvement in how their vehicle runs, such as a smoother drive and improved fuel mileage, very quickly.

Do Fuel Injector Cleaners Really Work?

It’s unclear whether fuel injector cleaners really work. In fact, from the research that I’ve done, there doesn’t appear to be any scientific information to support the claim that they are effective. I’m not claiming that they don’t work but I’m not sure what independent body has done the testing and can demonstrate proof that fuel cleaners will effectively clean and remove residue and by-products from within a vehicle’s fuel system.

The EPA regulates fuel additives which means that all additives, including fuel cleaners, must be registered with the EPA but this has nothing to do with whether the fuel injector cleaner works. The EPA stated in a 2011 report that they do not test or certify fuel injector products

From the EPA:

Many fuel additives are advertised to improve fuel economy, reduce exhaust emissions, or both. Some advertisements claim these products have been endorsed or approved by EPA. However, EPA does not endorse, approve, or certify fuel additives.

EPA does require fuel additives to be ‘registered’ but EPA does not test candidate products for engine efficiency, emissions benefits, or safety as part of the registration process. To register an additive, manufactures must report the chemical composition Office of Transportation and Air Quality EPA-420-F-11-036 August 2011 Consumer Information 2 along with certain technical, marketing, and health effects information.

In some cases the manufacturer may be required to conduct testing or literature research to assess potential emissions health effects. The EPA registration process does not include a check of manufacturer product efficacy claims. In other words, EPA does not determine whether or not the fuel additive works as advertised. Registration does not represent EPA endorsement of the product

How Do Gas Fuel Injectors work?

Fuel injectors work by sending fuel through your fuel system. How A Car Works does a great job at explaining how a basic fuel injection system works:

All modern petrol injection systems use indirect injection. A special pump sends the fuel under pressure from the fuel tank to the engine bay where, still under pressure, it is distributed individually to each cylinder.

Depending on the particular system, the fuel is fired into either the inlet manifold or the inlet port via an injector . This works much like the spray nozzle of a hose , ensuring that the fuel comes out as a fine mist. The fuel mixes with the air passing through the inlet manifold or port and the fuel/air mixture enters the combustion chamber.

Some cars have multi-point fuel injection where each cylinder is fed by its own injector. This is complex and can be expensive. It’s more common to have single-point injection where a single injector feeds all the cylinders, or to have one injector to every two cylinders

Here’s another great description from How A Car Works about two common fuel injector systems, (2) continuous injection and (2) timed injection (pulsed injection)

The injectors through which the fuel is sprayed are screwed, nozzle-first, into either the inlet manifold or the cylinder head and are angled so that the spray of fuel is fired towards the inlet valve .

The injectors are one of two types, depending on the injection system. The first system uses continuous injection where the fuel is squirted into the inlet port all the time the engine is running. The injector simply acts as a spray nozzle to break up the fuel into a fine spray – it doesn’t actually control the fuel flow. The amount of fuel sprayed is increased or decreased by a mechanical or electrical control unit – in other words, it is just like turning a tap on and off.

The other popular system is timed injection (pulsed injection) where the fuel is delivered in bursts to coincide with the induction stroke of the cylinder. As with continuous injection, timed injection can also be controlled either mechanically or electronically.

The earliest systems were mechanically controlled. They are often called petrol injection (PI for short) and the fuel flow is controlled by a mechanical regulator assembly. These systems suffer from the drawbacks of being mechanically complex and having poor response to backing off the throttle.

Mechanical systems have now been largely superseded by electronic fuel injection (known as EFi for short). This is thanks to the increasing reliability and decreasing costs of electronic control systems.

How Does Diesel Fuel Injection Work?

If you have a diesel engine, you can learn about diesel fuel injection from How A Car Works:

The fuel injection system in petrol-engined cars is always indirect, petrol being injected into the inlet manifold or inlet port rather than directly into the combustion chambers. This ensures that the fuel is well mixed with the air before it enters the chamber.

Many diesel engines, however, use direct injection in which the diesel is injected directly into the cylinder filled with compressed air. Others use indirect injection in which the diesel fuel is injected into the specially shaped pre-combustion chamber which has a narrow passage connecting it to the cylinder head.

Only air is drawn into the cylinder. It is heated so much by compression that atomized fuel injected at the end of the compression stroke self-ignites.

FAQs For How Often Should I Use a Fuel Injector Cleaner

What’s the difference between a fuel system cleaning service and a fuel injector cleaning service?

When taking your vehicle in for service, be sure that you understand exactly whether they will be doing an entire fuel system service that includes a fuel injector cleaning or just a fuel injector cleaning.

In speaking with several mechanics, it appears that a fuel system cleaning service usually includes the fuel injector cleaning but it includes a lot more cleaning.

According to Firestone Complete Auto Care, their fuel system cleaning service includes eight steps:
1. Clean the fuel system from the gas tank by adding a premium formula fuel system cleaner.
Fuel injector cleaning or carburetor cleaning, intake control valve, and combustion chambers with fuel system cleaner.
2. Use a fuel system cleaner to purge water from the fuel system.
Lubricate valves, cylinders, injectors, and rings.
3. Remove varnish, dirt, carbon, and other deposits from the throttle body and throttle plate.
Lubricate the throttle body and throttle moving parts with a corrosion inhibitor to prevent scoring and future deposit buildup.
4. Dissolve deposits from the engine’s intake manifold valve and runners, intake control valves, and eliminate combustion chamber deposits with a two-stage intake deposit cleaner.
Leave residual engine cleaner in the engine to soften hard carbon deposits over time and reduce long-term build-up in catalytic convertor.

Do you need to replace your fuel filter when getting a fuel system cleaning service, a fuel injection cleaning, or using a fuel injector cleaner?

Unless there’s a compelling reason to replace your fuel filter when getting either a fuel system cleaning service, fuel injection cleaning, or using a fuel cleaner, you don’t need to replace it.

However, according to

The rule of thumb when replacing a fuel filter on an older model car is at least every 2 years or 30,000 miles.

On newer models, this interval can run longer. The best way to tell if your fuel filter needs replacing is to have the mechanic do a fuel pressure test.

This lets the mechanic know how much PSI the fuel pump is generating at the fuel rail, with a faulty fuel filter reducing the pressure produced. The normal amount of pressure for a fuel-injected vehicle runs around 30 to 60 PSI.

What happens if my fuel injection system stops working?

If your fuel injection system stops working, fuel won’t be delivered to the engine, it will fail, and your vehicle will stop working. Once you’ve confirmed that your fuel injection system has stopped working, you’ll need to replace it with a new one, possibly like this Edelbrock Fuel Injection Kit or this ACDelco Fuel Injector Kit for GM vehicles.

There are 3 symptoms that might indicate that your fuel injection system might be failing:

1. Engine stutter, hesitation, or misfire could indicate a clogged injector
2. A decrease in fuel efficiency (lower fuel mileage than you typically get)
3. Difficulty starting or rough idling could also indicate that you have a clogged fuel injector

How often should I use Lucas Fuel Injector Cleaner?

Lucas recommends using their fuel injector cleaner as follows:
The recommended dosage is 2-3 ounces of Fuel Treatment for every 10 gallons of gasoline or diesel fuel. Pour Lucas Fuel Treatment directly into the fuel tank. Exceeding the recommended dosage is not harmful to your vehicle.
As a guideline, their products should last:
5.25oz Bottle – One bottle treats up to 25 gallons of fuel.
1 Quart/32oz Bottle – One bottle treats up to 100 gallons of fuel.
1 Gallon/128oz Bottle – One bottle treats up to 400 gallons of fuel.

Does using a fuel injector cleaner remove deposits from the combustion chamber?

Yes, using a fuel injector cleaner will remove combustion chamber deposits.

Do you need to replace your fuel pump when your fuel system stops working?

No, you don’t need to replace your fuel pump when your fuel system stops working. It’s possible that you have a fuel pump problem but your mechanic will run tests to confirm. If you need to replace your fuel pump, consider an Edelbrock fuel pump or an Aeromotive fuel pump.

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