How do you know if your fuel injectors are bad

16 Oct 2023

Faulty fuel injectors can cause havoc with your car. Fixing or replacing them will help prevent serious engine damage and improve your car’s performance.


Injectors can get damaged from poor quality fuel, corrosive injector cleaners and clogged fuel filters.

When an injector gets clogged or dirty, the fuel going to your engine will be restricted. This can cause a lean fuel/air mixture which in some cases may damage your engine. Symptoms to watch for include:

Difficulty starting

Uneven idling

Bad gas mileage

Poor performance

Smell gas

If your car is struggling to start, won’t idle or feels slower than usual, you may have faulty fuel injectors. If you smell gas and your stalling while idling or experiencing a rough idle, your fuel injectors may be stuck open. Has the ‘check engine’ light also illuminated? Then you should immediately get your injectors checked out.

If you suspect that your injectors are faulty, and still want to conduct a test, you can check the injector’s coil. You will need a digital multi-meter and the resistance valve for the coil inside of the injector.

There are several other ways to test fuel injectors including checking for the circuit control, but most others are software-based and require you to test on a professional equipment which is called diesel fuel injector common rail test bench. With this method of testing, you can visually inspect and diagnose your fuel injectors.

Diagnosing a bad fuel injector early is important because it can help prevent further damage to your engine. A faulty fuel injector can cause poor performance, decreased mileage, and an increase in emissions from your vehicle. It can even lead to engine failure if not addressed promptly since running lean can burn out a piston. Early diagnosis can also save you time and money by preventing the need for more extensive repairs in the future.


Some issues are inevitable, but most of the time, fuel injector problems can be mitigated or prevented altogether. To prevent fuel injector problems, it is important to keep up with regular maintenance on your vehicle. If you need wheel repair machine, please contact us at any time, we are manufacturer of this kind of machine for over 10 years and we can provide you with the best price.

How do you know if your fuel injectors are bad

Keywords: wheel repair machine

Originally published 16 Oct 2023, updated 16 Oct 2023.

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