Skip the auto shop - Our mechanics make house calls
  1. Home
  2. Articles
  3. Symptoms of a Bad or Failing Fuel Injector

Symptoms of a Bad or Failing Fuel Injector

fuel injector

Fuel injectors are an engine management component that is found on the vast majority of road going vehicles. They are a part of the vehicle’s fuel system and act as the nozzles that spray the fuel into the engine. They are controlled by the engine computer and operate by spraying the fuel in specific patterns and at specific timed intervals that will optimize engine performance. They are found on the vast majority of road going vehicles in one form or another. Because they are a part of the fuel system, any problems with the fuel injectors can cause all sorts of engine performance issues, that can sometimes even render the vehicle undrivable. Usually a bad or failing fuel injector will produce a few symptoms that can alert the driver of a potential issue

1. Engine misfires and decrease in power, acceleration, and fuel efficiency

One of the most common symptoms of a potential problem with a fuel injector is engine performance issues. If any of the vehicle’s fuel injectors have an issue, the air fuel ratio of the engine will be upset, which can result in performance problems. A faulty fuel injector can cause the vehicle to experience misfires, a loss in power and acceleration, a reduction in fuel efficiency, and in severe cases can cause stalling or prevent the engine from running at all.

2. Fuel odor

Another common symptom of a potential issue with a fuel injector is a fuel smell. Injectors hold high pressures which over time can cause them to leak at the nozzle or at the seal that is located at the tip of the injector. A leaky injector will excess fuel into the combustion chamber of the engine, while a leaky seal will leak fuel at the base of the injector. Both can affect engine performance, specifically fuel efficiency, and both will usually produce a noticeable fuel smell. Any sort of fuel smells should be addressed as soon as possible in order to prevent them from becoming a potential safety hazard.

3. Check Engine Light comes on

Another symptom of a potential issue with a fuel injector is an illuminated Check Engine Light. If any of the fuel injectors become clogged and cause a misfire, or experience an electrical issue the computer will set off the Check Engine Light to alert the driver of the issue. The Check Engine Light can also be activated by a wide variety of other engine management issues, so having the computer scanned for trouble codes is highly recommended.

Because of their role as the nozzles that provide the fuel that allows the engine to run, fuel injectors are a very important component to the overall operation and drivability of the vehicle. If your vehicle is displaying any of the symptoms above, or you suspect that your vehicle may be having an issue with one of the fuel injectors, have the vehicle diagnosed by a professional technician, such as one from YourMechanic, to determine if any of the fuel injectors need to be replaced.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Still not sure about your car's issue?
Diagnose your car
What kind of issue are you experiencing?
Brakes are squeaking
Car is not starting
Car is overheating
Car is shaking (vibrating)
Fluids are leaking
Heating and A/C
Smoke or steam is coming out of the car
Warning light is on
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

Symptoms of a Bad or Failing Timing Belt
Common signs include a ticking noise coming from the engine, an engine that won't turn over, engine misfires, and oil leaking in front of the motor.
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
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...


Related questions

Q: My Toyota Avensis 2006 has had a dramatic Fall in MPG - pre and post-service

Hi there: There are multiple reasons why recent service might negatively impact fuel economy on newer vehicles. As the vehicle continues to operate, the ECU (engine control unit or module) continues to learn and make adjustments to ignition timing, fuel...

Q: Truck wont accelerate over 20mph. what can it be

Either you have a blocked exhaust like a bad converter, a muffler clogged from a broken up converter, or you have a bad ignition module or fuel pressure problem. First try replacing the fuel filter to see if it is...

Q: Car will not stay on after starting it sometimes

Hello, I'm curious if there are any problem codes set (they may or may not cause the Check Engine light to illuminate). If so, these will be helpful. Most auto parts stores will read these for you for free. I...