Skip the auto shop - Our mechanics make house calls
  1. Home
  2. Articles
  3. What Causes Fuel Injectors to Get Clogged or Dirty?

What Causes Fuel Injectors to Get Clogged or Dirty?

fuel injector

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.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
The Traveler’s Guide to Driving in Malaysia
CraigBurrows / Shutterstock.com Malaysia is a popular destination for many tourists today. The country has amazing sights and attractions that you will want to explore....
How to Get a Louisiana Driver's Permit
s licensing program. The first step in this program is to obtain...

Related questions

Q: Odometer has lines, won't start unless I put fuel in the intake. The fuel pump keeps running and doesn't shut off? Seems like the truck wants to start.

Hi there. From the description you have provided, you've replaced the fuel pressure regulator, the fuel pump never shuts off and puts fuel in the throttle body, it runs until the fuel is gone, and the odometer has lines instead...

Q: Throttle Body and fuel injector cleaning normal to do at my miles? Dealership saying I should do it.

It may be a good idea to have the throttle body and injectors cleaned at regular times but you do not have to have it done now unless you are having a problem with how the engine is running. If...

Q: Check engine light is on. The gas cap is okay and the vent sensor by crankcase seems okay too. What could it be?

The issue could be the evaporative emission vent purge valve on the vapor charcoal canister. I recommend using a sniffer that is used for butane and check for a fuel leak around the vent purge valve and see if there...