What Are Fuel Injectors and How Do They Work?

Fuel injectors are responsible for regulating the direct injection of fuel into the diesel engine’s combustion chamber. Here, the fuel is mixed with air and spontaneously combusts. Releasing the fuel at the precisely correct time and pressure is vital for efficient combustion in a diesel engine, which is why fuel injectors are such important components.

Inefficient air-fuel mixing can leave unburned particles inside the combustion chamber, resulting in higher emissions as well as diesel knocking. These are examples of diesel engine problems you’ll want to avoid in your fleet!

Types of Fuel Injectors

It’s worth noting here that there are different types of fuel injectors, including both gasoline and diesel fuel injectors. In this article, we’ll focus solely on the diesel type. The three main types of diesel fuel injectors include:

Used in modern diesel engines, common rail diesel injectors work at high pressures and spray fuel into the combustion chamber for efficient combustion.

Used in heavy-duty diesel engines, a unit injector system features an individual pump integrated into each injector. This setup ensures precise control over fuel delivery.

Used in older diesel engines, mechanical injectors rely on mechanical fuel pumps to deliver fuel to the injectors.

So, how does a fuel injection system work? Read our breakdown below.

In a diesel engine, your fuel is supplied to the injectors from the fuel tank where the fuel pump pressurises it.

Most diesel fuel injectors are controlled by the engine’s electronic control unit, which determines the precise timing of fuel injection directly into the combustion chamber. The injectors use high pressure to inject fuel directly into the combustion chamber.

When the piston gets closer to the top of its stroke, an electrical signal triggers an electromagnetic valve (the solenoid) within the injector, activating the injector’s needle, which lifts. This enables the fuel to flow through the injector nozzle into the combustion chamber. The nozzle has tiny holes that atomise the fuel into a fine mist, perfect for mixing with air.

In many diesel engines, the injector works by firing multiple pulses of fuel during a single power stroke, which helps enhance combustion quality and reduce harmful emissions.

For more information on the inner workings of your engine, explore how diesel engines function.

Several different symptoms can indicate when your fuel injectors are malfunctioning, which can also suggest whether you need fuel injector cleaner. Some of the most common fuel injector faults to look out for include:

Reduced engine performance

If you notice reduced engine performance, this could be a sign that your fuel injectors aren’t functioning properly. If your injectors fail to deliver complete combustion, they may even contribute to your engine overheating, as the fuel is burned unevenly.

Engine misfires

An engine misfire occurs when your diesel engine doesn’t ignite fuel in one or more cylinders. Misfires can happen if the injectors aren’t delivering the right amount of fuel, often a result of clogging or wear and tear.

Rough or uneven idle

A rough or uneven idle, which causes your engine to shake or struggle to stay running, can result from the injectors not spraying fuel effectively.

Increased fuel consumption

Your diesel engine may be burning more fuel than necessary if you have a problem with your injectors, resulting in higher fuel costs and lower fuel efficiency. This can also result in higher emissions, releasing more pollutants than normal.

Your engine light comes on

A specialist from our team can read the diagnostic codes to determine if your diesel fuel injectors need cleaning or replacement.

Deposit build-up

If you’re having issues with your vehicle’s fuel system or have struggled with carbon build-up issues in the past, cleaning injectors can help clear these deposits.

If your fuel injector issue requires more than just a regular clean, you may need to seek replacement parts. Here at Foxwood Diesel, we have years of experience in cleaning and replacing fuel injectors, so we can take care of this for you, offering new and reconditioned part options depending on your specific requirements.

This means that you never have to worry about making a big and complicated fix yourself – we manage everything to maintain engine quality and get your fleet back on the road in no time!

To avoid faulty fuel injectors in the first place, consider the following top tips below.

1. Use a high-quality fuel

The diesel fuel you use can affect your fuel injectors, so make sure the one you use is contaminant-free. Consider using a fuel additive or diesel bug treatment to help out.

2. Clean your injectors regularly

Regularly cleaning your injectors can help tackle any clogged areas and sweep away any dirt and debris before they become too much of a problem.

3. Replace your fuel filters

As you know, filters don’t last forever, and clogged filters can impact fuel flow. Replace them in line with your manufacturer’s recommendation to limit damage to your injectors.

4. Service your injectors with Foxwood Diesel

At Foxwood Diesel, we can inspect and service your diesel fuel injectors, ensuring that any problems are identified and addressed professionally at an early stage. We’re all about keeping engines in good condition, and that includes your fuel injectors!

While not directly making your fleet faster per se, if your fuel injectors are clogged or improperly functioning, they can cause a noticeable poor acceleration and reduced power. When working correctly, the injectors help the engine offer an elevated feeling of acceleration and performance.

That’s a wrap! Hopefully, you’re more familiar with what fuel injectors are and how they work. If you still have a question, don’t hesitate to contact us today and a member of our team will be happy to pick it up.

Here at Foxwood Diesel, we’re experts in cleaning and replacing fuel injectors. If you have a faulty component, we can provide the maintenance assistance you need and discuss our full range of services with you over the phone or in person. We can’t wait to hear from you and get your bus fleet back up and running!