How to Flush a Fuel Injector

The easiest way to distribute a liquid or vapor through any propulsion system is to ensure that the system is clean and free of obstructions. This applies especially to today's modern fuel systems, which distribute fuel and air mixtures into the cylinder head intake manifold by way of the fuel injector. When the fuel injectors are clean and free of blockages, the engine runs smoothly and efficiently. When they are dirty, it can significantly impact the operation of the entire engine. There are a few warning signs of clogged fuel injectors, including a reduction in fuel economy or engine power, or black smoke coming from the exhaust.

Method 1 of 2: Using fuel injector cleaning additives

Material Needed

Step 1: Purchase the fuel injector cleaning additive. Most of the time, DIY mechanics will start with this method to clean their fuel injectors if they begin to notice any of the common warning signs. The first step is to buy a small bottle of formula, enough for three to four gas tank fill ups.

If you choose to use it, the recommended dosage of Lucas Oil's Fuel Treatment is 2 to 3 ounces per 10 gallons of fuel.

Step 2: Pour the fuel treatment into the gas tank. Make sure to do this after filling the fuel tank. Add the recommended dosage after you determine how much fuel you added.

Keep it inside your vehicle to make sure you can add it with every fill up and on a consistent basis for best results.

Step 3: Continue this process for a minimum of three to four full tanks. The drawback of using fuel additives is that they are added in very small amounts so as to not negatively impact the performance of the vehicle or to trigger alerts caused by most fuel-related sensors.

It will take some time for them to work, but if done correctly, they should do a good job cleaning up the fuel injectors as well as the entire fuel system.

Method 2 of 2: Using fuel injector kits

Materials Needed

  • Fuel injector cleaner kit
  • Fuel injector cleaning solution
  • Hand tools for removing fuel lines, disconnecting the fuel pump or power to the fuel pump
  • Safety equipment including gloves and safety glasses
  • Scan tool

hanging the tool

Step 1: Hang the fuel injector cleaning tool from the hood. The system is air pressure applied but needs to be hung straight in order to work correctly.

pouring the cleaner

Step 2: Pour the fuel injector cleaner into the cleaner tool. The fuel injector cleaning liquid is comprised of special additives as well as gasoline.

When you attach this device to the fuel system, the engine will run on the liquid inside the device. Once the liquid runs out, the engine will shut down.

You need to always refer to the exact instructions that the product manufacturer supplies in order for this process to work correctly.

Step 3: Disconnect the fuel lines on the fuel rail. Most fuel injector cleaning tools have an attachment that connects the fuel line from the fuel pump to the unit, and an attachment from the unit back to the fuel rail.

If your system does not have this attachment, you'll have to disconnect the fuel line and disconnect power to the fuel pump so the unit does not supply fuel as the fuel injector cleaner is in use.

If your fuel injector cleaner has a connection to attach the fuel line to the unit, remove the fuel line from the rail and attach it to the unit. Then attach the fuel line from the unit back to the fuel rail.

If your fuel injector cleaner does not have this connection, you'll have to remove power to the fuel pump, remove the fuel line connection to the rail and then install the fuel line from the unit to the fuel rail.

Step 4: Run the cleaner through the fuel injectors. Connect the fuel line from the cleaning tool to the fuel rail. Start the engine with the fuel line open from the cleaner to the fuel rail.

Let the engine run until the tank on the fuel injector cleaner tool is empty. Disconnect the fuel line from the tool and reconnect the primary fuel supply line from the fuel pump to the fuel rail. Reattach power to the fuel pump (if you had to remove it earlier).

Step 5: Start the engine, check for error codes or clear existing codes. One of the drawbacks of using this system is that it tends to trigger sensors that monitor the fuel injection system.

If you complete this process, you'll need to have access to a digital scanner in order to clear these error codes.

If you've completed all of these steps and still can't find out the source of the problem, or need an extra set of professional hands to help fix it, contact YourMechanic to find a local ASE certified mechanic that will be happy to assist you. A diagnostic check will determine if you need to have the fuel injectors replaced.


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Recent Fuel Injector Replacement reviews

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Rating Summary
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William

34 years of experience
301 reviews
William
34 years of experience
Cadillac STS - Fuel Injector - Phoenix, Arizona
He came to the first appointment explained what was happening he was able fix and get me a quote for the issue I had and scheduled me quick for the other issue I had was able to explain with my certain items were not needed even though online portal stated was needed. Only paid for the services required to fix the issue. He kept in contact with me to advise on the repair status and the final result. Nice to have the mechanic come to you. Would recommend William very courteous.
Mercedes-Benz 380SL - Fuel Injector - Sun City, Arizona
William was wonderful. Very knowledgeable and hardworking. Absolutely the best of the best mechanic.

Matthew

33 years of experience
991 reviews
Matthew
33 years of experience
Chevrolet Corvette - Fuel Injector - Newport News, Virginia
Matthew was awesome professional patient with my questions very knowledgeable and insightful I'm so grateful for his help and I will definitely request his services in the future I thank you!
Mitsubishi Raider - Fuel Injector - Newport News, Virginia
Great Mechanic!!! Work was complete in a very timely manner. Much easier than having go through the gymnastics of having a dealership perform the work.

Torrieanto

12 years of experience
632 reviews
Torrieanto
12 years of experience
Chrysler Town & Country - Fuel Injector - Saint Petersburg, Florida
Torreanto replaced all 6 injectors on my 2008 Town and Country for an extremely reasonable cost. He is a very competent mechanic with excellent experience. His troubleshooting and analytical skills were very apparent during our discussion of the work at hand. I really enjoyed talking with him on an engineer to engineer level. The job was completed in a timely manner with careful attention to detail. My car is running smoothly again with excellent power. He was also helpful in discussing other issues that were identified that may need addressing in the future. I will definitely look for him to do any necessary work on my van in the future.
Volkswagen Jetta - Fuel Injector - Riverview, Florida
Torrieantos arrived on time to complete the repairs. He was courteous, knowledgeable and got the car back up and running like new.

Zachary

9 years of experience
43 reviews
Zachary
9 years of experience
GMC Yukon - Fuel Injector - Hockley, Texas
Nice guy, friendly and courteous. He did good work. While it did not fix the overall issue with the car, what he was tasked to do was done well and knocks off a possible cause of my misfire. Thanks Zachary!
Jeep Cherokee - Fuel Injector - Cypress, Texas
Zach was on time, fixed the diagnosed issue and pointed out another problem, which could have resulted in a major safety issue if not repaired. He was not scheduled to work the rest of the day, but fit me in and got my car back to good condition! Thanks Zachary.

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