What Is A Fuel Injection System?

Educational

Nov 25th, 2020

What Is A Fuel Injection System?

What’s the role of the fuel injection system in your vehicle? If you understand even just a little bit about combustion engines, you'll know that they require air and fuel to work. The basic idea is that the engine will take in air and fuel, then pressurise and combust that mixture to generate power. But how does it ensure it gets the right amount of fuel, at precisely the right moment? That’s where the fuel injection system comes into play. 

It uses sophisticated sensors and other electronics to deliver (or ‘inject’) the correct amount of fuel at the proper times. That way, your engine can operate at the optimum level of fuel efficiency.

In this article, you're going to learn everything you need to know about your fuel injection system. Not only that – you'll even learn how and why it's superior to carburettors, which filled a similar role in the past.

Keep on reading! 

What is a fuel injection system?

In short, a fuel injection system is one that uses complex sensors and other electronics to deliver fuel into the engine’s combustion process. More importantly, it provides the right amount of fuel at precisely the right moments, to ensure that your engine generates power more efficiently.

Fuel injection systems take over the job that carburettors (spelt ‘carburetor’ in American English) used to do. In older vehicles, a carburettor was the mechanical tube that would mix air and fuel in valves before combustion. 

However, carburettors are relatively low-tech and aren’t as efficient at mixing fuel and air the same way fuel injection systems do these days. Generally, carburettors have more fragile components compared to fuel injection systems. 

Plus, they don’t mix the fuel and air consistently, so the engine’s performance ends up not being smooth. That’s why most modern vehicles now use fuel injection systems instead of carburettors.

How does a fuel injection system work?

Inside your car, a fuel pump delivers pressurised fuel from your tank straight to the engine bay. There, the fuel injection system will distribute it to each cylinder.

When the fuel enters the engine to be a part of the combustion process, it usually comes out in the form of a fine mist. That way, it can mix with the air much more efficiently before igniting the mixture to generate power.

Here’s where it gets interesting. Typically, the system will ‘inject’ the fuel into the engine through either the inlet manifold or the inlet port. What this means is that most engines do not receive fuel injected directly into individual cylinders.

The reason for this is simple: separately injecting fuel into the cylinders is expensive and very complicated. It's much simpler to have the fuel injected into the engine through one point, or at the very least with one injector per pair of cylinders.

What happens when fuel injectors get dirty?

Like any car part that involves fluids, fuel injectors also get dirty at some point in its life. When that happens, the injectors can clog up and affect the delivery of fuel into the engine.

Remember: fuel injection systems are all about precision. They have to deliver the right amount of fuel at the precise time. With that in mind, it’s easy to see that clogged fuel injectors will affect the engine’s ability to combust all that fuel and air.

When your fuel injectors get dirty and eventually clog up, you’ll notice these issues:

  • Your car will not be able to accelerate smoothly as it usually does.
  • Your car will idle roughly, even when you’re not pressing on the gas pedal.
  • The most significant tell-tale sign: your Check Engine light will come on.

Check out another article for a more in-depth look at what happens when your fuel injectors get dirty or faulty, and what you can do about it.

How to maintain your fuel injection system

There are a few ways to maintain your fuel injection system, including the use of fuel additives, using pressurised injector cleaners, or removing them entirely for cleaning with specialised ultrasonic gear.

However, the easiest and most affordable method that most people use is to add special fuel additives directly into their fuel tank. These additives will travel through the system and gradually remove anything blocking the fuel injectors from doing their job correctly.

There is no fixed interval when you should clean your fuel injectors. However, most people keep it simple by doing it every time they go to the mechanic for regular maintenance. That method saves drivers from making an extra trip or forgetting to clean their injectors. 

Though, the only minor downside is that it’ll add to the final bill for that trip to the mechanic.

Why is fuel injection better than carburettor?

Fuel injection systems are better than carburettors, without a doubt. 

Here are some of the advantages of fuel injection systems:

Better fuel efficiency

With all the complex electronics working together in a fuel injection system, your engine always gets the right amount of fuel and only at the correct times. That means less wastage and a more efficient operation overall.

Better power and performance

A fuel injection system can ‘think’, so it’ll help your engine generate better power and performance when the situation calls for it.

Lower emissions

Less fuel wastage and higher efficiency mean lower emissions. So, in the grander scheme of things, fuel injection systems are better for the planet.

Some traditionalists may argue that carburettors are better, preferring the classical way of doing things. 

Unfortunately, carburettors have significant disadvantages that include:

Inconsistent fuel and air mixture

Carburettors are mechanical, not electronic like fuel injection systems. Therefore, it’s harder for them to be precise, leaving you with inconsistent fuel and air mixtures that affect performance.

Lower fuel economy and worse emissions

Because of the lack of consistency and efficiency, you get a lower fuel economy with a carburettor while also generating more emissions.

A minor delay in engine response 

Carburettors take a little bit of time (perhaps a half-second or so) to respond when you press your foot on the gas pedal. That might not sound like a big deal, but most people are used to instant responses from their car and will find this very annoying.

If you’re ever in the market for a new fuel injector, or if you want to replace your fuel injection system altogether, head over to Carpart.com.au. There, the Parts Finder is all you need to get your hands on what you need. Start filling out that part request form now!


By Ray Hasbollah