What Causes Fuel Injectors to Get Clogged or Dirty?

Fuel injectors are responsible for getting fuel into the engine. Fuel injection systems either work via a throttle body containing a couple of injectors that send fuel to multiple cylinders at once, or via injectors that deliver fuel directly into each cylinder individually. The injectors themselves spray gas into the combustion chamber like a spray bottle, allowing the gas to mix with air before ignition. The fuel is then ignited and the engine keeps on moving. If the injectors become dirty or clogged, the engine struggles to run as smoothly.

How fuel injectors work

Whenever an internal-combustion engine is powered down, the combustion chambers have leftover fuel/exhaust hanging around. While the engine cools, the vaporized gases settle on every surface in the combustion chamber, including the fuel injector nozzle. Over time, this residue can reduce how much fuel the injector can deliver to the engine. There is not much you can do to prevent this, but if the engine has worked particularly hard (lots of uphills or high temperature) it may be a good idea to let it cool down a little before shutting the engine off. Driving more gently towards the end of a trip can extend the life of the fuel injectors.

Aside from the fumes and fuel itself, the fuel injectors can get clogged up by debris. This can either come from gas or from the fuel system itself. Gasoline with impurities in it is less common these days, and most major gas stations have consistently high-quality gas. Still, debris can get into the tank and then into the fuel system. The fuel filter catches the majority of impurities but a small amount may make it past the filter. If there is water in the fuel system, corrosion can happen within the lines and fittings of the fuel system. This corrosion can cause debris to be jammed in the injectors.

What services can fix this issue?

In the case of simple debris in the injectors, a fuel injection flush is a cost-effective way to improve fuel injector performance. For cooked-on residue, it usually requires a full ultrasonic cleaning to get the fuel injectors back into fighting shape. For particularly old or inexpensive injectors, replacement may be the best solution.


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Robert

31 years of experience
641 reviews
Robert
31 years of experience
BMW 328i L6-3.0L - Fuel Injector - Mountain View, California
Robert brought the whole mechanic shop with his amazing knowledge/experience into my garage, and he was very flexible. He paid attention to every details during the repair process and didn’t bother to explain on my questions. Most importantly, Robert is a very honest man whom you can count on...^^
GMC K1500 Suburban - Fuel Injector - San Jose, California
I cannot begin to describe how great of a mechanic Robert is not only did he constantly keep me updated , was very straightforward , extremely professional and did absolutely excellent work we'll probably never use another mechanic other than him ever again I would recommend him to absolutely anybody

William

34 years of experience
517 reviews
William
34 years of experience
Cadillac STS V8-4.6L - 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
1210 reviews
Matthew
33 years of experience
Chevrolet Corvette V8-5.7L - 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 V6-4.0L - 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.

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