Car Fuel Injector

When You Should Replace Your Car’s Fuel Injector

21 May, 19

It’s safe to say that in the 21st century, we simply could not live without our cars. We use them day in and day out and would be really stuck if anything should happen. Yet still, many of us neglect key maintenance practices for our vehicles. Low maintenance standards can severely impact the longevity of your car and rack up costly repair bills.

In this article, we will take a closer look at your car’s fuel injectors, discus what they are, look at some signs which indicate they could be failing, and talk about why seeking maintenance is essential.

What are fuel injectors?

The sole purpose of a fuel injector is to inject the correct amount of fuel into the engine to create the optimal air/fuel ratio required for easy ignition. The injectors are electronically-controlled by the onboard computer. By using air data given to it by the mass air flow sensor, it calculates the correct amount of fuel to provide. A fully-working fuel injector should not only provide the engine with fuel but also deliver this at the right pressure, angle, and spray pattern.

Signs of Worn-Out Injectors

There are many signs which can indicate an issue with your fuel injectors, be it that they are clogged, damaged, or faulty. The list below describes some of the most common signs and symptoms.

1. Restricted – If a fuel injector becomes restricted from clogging, even if it is as little as 10% of the entire aperture, the air/fuel ratio in the engine can become lean, leading to what is known as a lean misfire. This is when either the amount of fuel or the amount of air becomes off ratio, making the fuel harder to ignite and combustion difficult.

2. Turbo – Blocked or dirty injectors can cause catastrophic engine failure in turbo charged cars. When a car goes turbo, it needs all the fuel the injectors can provide. Without it, the air/fuel mixture becomes lean, which can cause severe engine damage and a failure in turbo drive systems.

3. Heat Soak – This is one of the most common causes for injectors to become blocked. When the engine is turned off, the injectors experience something known as ‘heat soak’, where fuel evaporates in the nozzles, leaving behind residue. If not maintained, this will severely impede the functionality of the injectors. This issue is particularly seen in vehicles that are used primarily for short trips.

4. Misfires, Trouble Starting, Rough Idling – Due to clogged/faulty injectors causing a lean air/fuel ratio, you may find your engine misfires regularly, and becomes tricky to start. You will also start to notice that when you pause in traffic or at an intersection, your idling becomes rough and juddery. This is because ignition doesn’t only happen when starting your engine. It is a constant cycle. Therefore, rough idling will occur when this cycle is difficult for your engine to achieve.

5. Check Engine Light – Severe lean misfire will typically trigger the check engine light, as well as a misfire code. You can use this code to diagnose which fuel injector might be to blame.

6. Poor Performance – Of course, if the air/fuel mixture is incorrect, then you are leaving your vehicle to try to run in inopportune conditions. As with anything in life, you can’t expect supreme performance if the correct tools or supplies are not provided. Your car is no different.

Car Fuel Injector Check


It is possible to extend the life of your fuel injectors, and in fact, these parts don’t need to fail at all in your vehicle’s lifetime. While there is a degree of chance to this, good maintenance strategies dramatically increase the likelihood of longevity of your vehicle’s parts.

Seeking out experts for proper maintenance and repairs is always a smart decision. If you live in the Santa Barbara or surrounding areas of California, make Santa Barbara Autowerks your number one stop. We are master technicians in German motoring. We offer five-star service and a 2 year/24,000 mile warranty. You are guaranteed to drive away happy with squeaky-clean fuel injectors to match.

Call Us Today!