At United, fuel injection is what we do. We like to think that we know a thing or two about it, so if you need any work done on yours, we’re the people you want to turn to.

That being said, it never hurts to have a bit more of an understanding of the subject, especially if you end up having to rely on someone a bit less knowledgeable and trustworthy than we are (unfortunately there are still plenty of dodgy dealers out there). That’s why we’ve put together this beginners guide to the main types of fuel injection. Have a read, and the next time you visit us (or your mechanic) you’ll be able to dazzle us with your knowledge.

Single-Point or Throttle-Body Injection

The earliest and most simple type of fuel injection system, the single-point method replaces the carburetor with one or two fuel-injector nozzles in the throttle body (which is the throat of the engine’s air intake manifold). While it’s less precise than other methods, it still meters fuel with more control than a carburetor and is less expensive and easier to service.

Multipoint or Port Fuel Injection

This method devotes a separate injector nozzle to each engine cylinder just outside its intake port, which is why it’s sometimes known as port injection. By shooting the fuel vapor this close to the intake port, this type of fuel injection system ensures that it will be fully drawn into the cylinder.

The main advantage of multipoint fuel injection is that it meters fuel more precisely than throttle-body designs and better achieves the desired air-fuel ratio. It also virtually eliminates the possibility that fuel will condense or collect on the intake manifold.

Sequential Fuel Injection

Also known as sequential port fuel injection or timed injection, this is a more advanced multiport fuel injection method. Unlike basic multiport injectors that spray all of their fuel at the same time (or in groups), sequential fuel injection triggers each injector nozzle independently. Timed just like spark plugs, they spray the fuel just before or as their intake valve opens. This improves fuel efficiency and reduces emissions.

Direct Injection

The ultimate in fuel injection technology, this method injects fuel past the valves and directly into the combustion chamber. Traditionally more common in diesel engines, direct injection is starting to pop up more and more in petrol motors. With even more precise fuel metering than other methods, direct injection also gives engineers yet another variable that can influence how combustion occurs in the cylinders and can be used in low-emission, lean-burn engines.

We hope that this introduction to the main types of fuel injection systems helped you become a bit more well informed. As one of the most important systems in your car’s engine, it’s not something that you want to risk when it comes to repairs and maintenance. That’s why our fuel injection services are some of the best in the entire city. Give us a call on (08) 9259 3000 or get in touch to find out more.