Auto Parts for Rebuilding Engines: A Guide to Performance Parts

Understanding Common Rail Injectors

You may already know that your car has a fuel storage tank. What you might not know is how the fuel gets to the engine to make it start, run, and power your vehicle. Here's a simple guide to help you understand fuel movement:

High-Pressure Circulation Pump

Your vehicle has a high-pressure circulation pump that helps pump fuel from your fuel tank to the engine at high pressure, through injectors and into the combustion chamber. How the pressurised fuel enters the fuel injectors depends on the design of the injectors:

  • Conventional injection systems – In standard injection systems, fuel pressure is generated by the high-pressure pump individually for each injection.
  • Common rail injectors – If a common rail injector is present, the high-pressure pump generates fuel pressure and injects it into the common rail. The common rail then acts as a high-pressure reservoir for individual injectors that inject fuel through cylinders into the combustion chamber.  

Why is A Common Rail Fuel Injector Recommended?

If you look at how a conventional injection system works, every time fuel needs to be injected into the combustion chamber, the high-pressure circulation pump needs to generate pressure and move the pressurised fuel directly to each injector. This is not efficient and might lead to high fuel consumption and high emissions from the exhaust.

A common rail injector shortens the distance the pressurised fuel has to travel and makes it available when needed because it is stored in the common rail (high-pressure reservoir). This enhances fuel efficiency, low consumption, low emissions and high engine power (when the engine needs fuel, there is a shorter travel distance).

Maintenance and Preventative Measures

Note that you need to maintain your fuel injection system to avoid component damage.

The first thing you need to do is ensure your fuel is clean. Your fuel filters should be inspected regularly and replaced when worn out or clogged.

Secondly, purchase fuel from reputable fuel stations and avoid fueling your car from fuel containers. If you must use a fuel container, ensure that it is clean and tightly sealed. Always confirm this before filling it with fuel even if you had stored it away after cleaning it. Fueling your car with contaminated fuel is asking for expensive problems.

Thirdly, avoid modifications, especially fuel injector modifications and components that are not recommended by car manufacturers. For example, avoid removing pressure-limiting devices, installing burred components, installing weak nozzles and mixing nozzle needles.