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    A Guide to Fuel Injectors: The Different Types and What to Consider When Buying One

    By on Last modified: June 23, 2022

    In order for your Holden to go forward, it needs to burn a mixture of fuel and air in the combustion chamber at a specific ratio. Every time you press the gas pedal, the throttle opens, allowing air to go in, and fuel injectors spray petrol at a precise timing to provide the required power. That being said, fuel injectors play a huge role in the performance of your Holden, and if you want to squeeze more power out of your engine, it’s important for the fuel injectors to be responsive and provide the optimum amount of fuel. 

    While your stock fuel injectors will do the job fine, if you’ve performed throttle modifications, they might not provide sufficient amounts of fuel, robbing you of potential gains. This is why a lot of people opt for aftermarket fuel injectors. When choosing these aftermarket Holden performance parts, there are quite a few things you need to consider, as it’s important you get the right product.

    Types of Fuel Injectors

    Close-up of differernt types of fuel injectors
    Source: vectormotorsports

    Based on your Holden model and year, the size and position of the fuel injector – there are two basic types of injectors available. These injectors vary in price, durability, construction and performance. Moreover, injectors used for diesel and petrol vehicles are different, and each is made for a specific vehicle. Replacing your stock injector with an aftermarket injector that’s too small can cause engine damage. On the other hand, getting an injector that’s too big will reduce performance at small throttle openings and result in idle problems. That being said, it’s necessary to fit the right injector into your Holden. There are two basic types of injectors – mechanical and electronic.

    Mechanical Fuel Injectors

    These fuel systems rely on a sophisticated fuel pump to provide pulses of fuel to the injector feeding the cylinders. The pressure of the upcoming fuel causes it to open, thus spraying the fuel into the combustion chamber. This engine pump features a series of pistons that are operated by camshafts, allowing them to generate the burst of fuel required. The output from the pistons, outside of regulation, may create a few changes to the mixture. As a result, the mixture is typically not ideal for the engine load.

    Electronic Fuel Injectors

    Electronic fuel injectors, as their name implies, feature electronic management. They provide camshaft-operated delivery of pressurised fuel, and the management of the timing is performed by the engine control unit. As a result, you get ideal timings and precise fuel management. The fuel pressure regulator features a mass airflow sensing element, allowing it to let through the right proportion of fuel. There are three types of electronic fuel injectors based on the way they receive the fuel – side-feed injectors, top-feed injectors and throttle body injectors. 

    Factors to Consider When Buying Fuel Injectors

    Close-up of installed fuel injectors

    Depending on the type of Holden you drive, the fuel injector that’s ideal for you will vary on a few factors. Getting things right is essential to getting optimum performance and mileage. The fuel injection process, as aforementioned, is crucial for your Holden’s combustion and emission formation. As fuel is injected, the fuel injector needs to vaporize and atomize it. The emission has to be kept low during the combustion. If you choose the wrong injector, it can lead to many problems. Here’s what you need to consider:

    Injector Length

    As stated above, replacing an injector with one that’s too small can result in engine damage from detonation. Replacing an injector with one that’s too big, on the other hand, will result in power loss at small throttle openings and idle problems. For that reason, you need to fit one that’s just right for your vehicle.

    Emission Levels

    If the fuel that comes from the injector doesn’t burn fully, you may get white smoke out of the tailpipe. This can also mess with the timing of the engine, and you should check for damage immediately.


    The timing of the fuel injector is essential. Failing to spray fuel at the right intervals can result in performance issues, and what’s the point in getting Holden performance parts if they actually hinder performance. To avoid timing issues, calibrate the injector properly.

    Spray Angle

    The spray angle needs to be right for the combustion of fuel. The angle can change from carbon deposits on the injector. To avoid this, use special injector cleaners every once in a while.


    Since injectors are relatively close to the engine, and full of fuel, it’s important that they’re capable of withstanding high temperatures. 


    Close-up of fuel injectors

    Bosch fuel injectors are arguably the most popular ones available. They’re made using superior materials and undergo rigorous testing. As such, they provide reliable performance you can count on. Delphi fuel injectors are also quite popular, as Delphi has been manufacturing quality engine parts for over 100 years. Autoline Products injectors are also an option, as they produce parts that exceed OEM standards and provide extra benefits that add to performance and longevity.