How to Clean Fuel Injectors

How to Clean Fuel Injectors

One of the most important components of the fuel injection system in modern cars (including the fuel system in all diesel engines and gasoline engines) is the fuel injectors.

Back in the very early days of internal combustion engine technology, the fuel was delivered using a mechanical carburetor, which was a far cry from today’s more sophisticated engine’s fuel injectors.

The fact is, this type of fuel system worked well for many years, but with the creation of onboard computers, new fuel delivery systems were subsequently developed.

The first systems worked very well, focusing mainly on replacing the carburetor fuel bowl and mixing chamber with fuel injectors.

The most recent systems – often seen in direct injection engines – place the injector right at the cylinder head, near the spark plugs. This method creates better fuel efficiency and throttle response and is often referred to as direct fuel injection.

It is these fuel injectors that we will focus on in this guide as we take a look at how to clean fuel injectors to improve the performance of your engine.

Let’s get to it.

What are the Fuel Injectors?

Despite common belief, fuel injectors are more than just electronically controlled devices used in a vehicle’s fuel system. Attached to the fuel rail, they are also designed to meticulously spray a perfectly measured amount of fuel mixed with the optimal air-fuel mixture directly into the combustion chamber of each engine cylinder.

The design is actually quite ingenious, leading to better fuel economy in addition to the added performance benefits.

But while they are ingenious, they are also flawed, to some degree: since they spray such small amounts of fuel, they are extremely susceptible to the effects of clogged fuel injectors caused by tiny particles and general carbon build-up.

Many people believe that the detergent in the fuel and the fuel filter will keep the fuel injector clean, but this is something of a misconception, as they will often require cleaning more diligently.

If and when the injector spray pattern is impacted, the on-board computer will immediately kick in and store a code. This is an advanced feature meant to protect the vehicle’s performance and fuel economy.

Most of the time, this will result in the check engine light coming on. If the problem is not promptly addressed, the car’s engine performance will almost certainly suffer as a result, leading to decreased fuel economy.

Actually, in extreme cases, like complete fuel system failure, the car may stall and not restart, as a worst-case scenario.

What Are the Symptoms of Clogged Fuel Injectors?

Quite often going unnoticed until it’s far too late, the build-up of deposits and potential clogging of the fuel injectors gradually deteriorates the performance of your vehicle. Usually, this happens slowly but surely over time.

Especially in older cars with high mileage, you may have already experienced some tell-tale performance issues. To help you identify the problem early on, here are a few symptoms that would warn you that your fuel injectors need to be cleaned:

  • The check engine light is illuminated.
  • The car is misfiring (the most common symptom that fuel injectors need cleaning).
  • The car has poor performance.
  • Fuel consumption has increased.
  • The car has a rough idle.
  • The car is sometimes hard to start (another common warning sign that the fuel injectors are partially or completely clogged.

Is Injector Cleaning Necessary?

Under normal circumstances, modern cars (including both diesel and gasoline engines) are designed to keep the fuel injectors operating at their best levels.

However, if your car is older and has high mileage, or if you frequently let your gas tank run low, you might want to clean fuel injectors yourself, using specialized kits or fuel injector cleaners. Ignoring this important maintenance task could lead to more serious engine drama later down the line.

Using a specialized fuel injector cleaning kit can be a very wise investment. These kits are very affordable and relatively easy to use if you have reasonable mechanical skills – and serve as a good example of the old saying: an ounce of prevention is worth a pound of cure!

Can I Clean My Fuel Injectors?

So, how to clean fuel injectors if you are a non-mechanic? Is this something you can realistically tackle on your own?

Well, the answer is both yes and no. This type of project demands a certain level of mechanical proficiency, as you’ll be dealing with the fuel system, vehicle electrical circuits, and combustion engine components. If your only prior experience with mechanical engines relates to topping up the windshield water reservoir, you should probably exclude yourself.

In other words, this is not an entry-level mechanic endeavor that should be taken on by someone with base-level mechanical skills. You need to know your way around an engine to some degree, at least.

If you are unsure about your skill level, you might want to consider fuel injector cleaner additives, which is a simpler maintenance option. Although less effective than a full fuel injector cleaning service, a fuel injector cleaner can provide some engine performance improvements, at the very least.

Do I Need Any Special Tools to Clean My Fuel Injectors?

This DIY maintenance project will require the acquisition of certain automotive parts along with your fuel injector cleaning kit. Presuming you have a standard mechanic’s toolset and fuel injector cleaners, here’s your checklist:

  • Specialized wrenches or socket set to remove the fuel injectors.
  • Cleaning solution specifically for fuel injectors. Use fuel injector cleaners that contain polyether amine (PEA), which is highly effective against stubborn carbon deposits.
  • Replacement O-rings for each fuel injector.
  • High-pressure rubber hose and hose clamps.
  • Electrical connectors, preferably with alligator clips.
  • Spill containment drip pan for any fuel runoff.

Before using fuel injector cleaners, make sure all your automotive repair tools and replacement parts are on hand. Proper preparation ensures a smooth DIY car maintenance process, minimizing the risk of engine performance issues down the line.

Step-by-Step Guide on How to Clean Your Fuel Injectors

Once you have the correct tools and any replacement parts needed, you are ready to tackle the project. Set aside about 1-2 hours for this project from beginning to end.

Here are the steps you need to follow to successfully clean your fuel injectors.

  1. Locate and remove one engine’s injector from the combustion chamber/cylinder on the engine. You can identify the fuel injector because it will have a fuel feed and electrical connection attached to it.
  2. Disconnect the injector from the vehicle’s fuel rail so that the in-flow opening is accessible. Remove the new fuel injector O-ring from the fuel injector, ensuring the fuel rail is intact.
  3. Disconnect the wiring harness connector from the fuel injector.
  4. Connect the rubber hose to the in-flow opening on the fuel injector and tighten it with a hose clamp so that it won’t leak.
  5. Connect the electrical leads with alligator clips to the injector. Polarity isn’t an issue, as the fuel injector will activate when power is applied.
  6. Connect one of the leads to the negative terminal on the car’s battery. Use the other lead to touch the positive terminal of the battery when you are ready to activate the fuel injector.
  7. Pour the fuel injector cleaner treatment into the hose. Now, touch the test lead on the positive terminal a few times to spray cleaner through the fuel injector.
  8. Switch to reverse flush the fuel injector. Simply remove the hose from the in-flow side and connect it to the out-flow side of the fuel injector.
  9. Add more injector cleaner to the hose. Activate the injector again by touching the test lead on the positive terminal a few times to clean the other direction.
  10. Remove the alligator clips from the fuel injector and reconnect the wiring harness connector.
  11. Reconnect the fuel injector to the fuel rail, slide on the new O-ring, and secure the fuel injector.
  12. Repeat the entire process for the remaining fuel injectors.

Frequently Asked Questions

0/5 (0 Reviews)