Diesel Engine Common Rail Injection Explained

We've talked a lot about issues you might experience with your diesel engine common rail injectors. But it's not all about the problems! You also get  a lot of benefits for having this kind of fuel injection system in your diesel engine.

So, today we're taking you through how the common rail injection system works in your diesel engine, and some of the benefits it brings.  

Want to know more about how to identify problems with your common rail injectors? Check out our blog, An In-Depth Look At Diesel Engine Common Rail Fuel Injector Problems.

You can also watch our video to learn more about how common rail injectors work in your diesel engine:



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How Does the Common Rail Injection System Work?


common rail injectors fuel lines | Highway & Heavy Parts


As you can probably guess, the common rail injector system works a little bit differently than conventional injectors. These injectors use a high-pressure rail that brings the fuel to the individual injectors at a constant pressure. 

The common rail system is comprised of your high pressure pump, or your common rail pump. This pump has a metering valve on it—an MPROP or a pressure regulator. This is going to feed your common rail, which is a tube with a rail sensor on it.

The rail sensor just meters how much pressure is in that rail. So, if you have a high pressure or a low pressure deviation, it'll throw a code to your ECM.

From the rail it goes through the tube or injector lines to your injectors, which fire by your engine control module. The way that the injector fires and how fast it fires at higher pressures allows for quicker and cleaner combustion inside the engine, especially when compared to conventional injectors. 

Do you know the difference between different types of injectors systems? Read our post on the differences between common rail and unit injectors


What are the Benefits of Common Rail Injectors?


common rail injector benefits | Highway & Heavy Parts


As with any different system in your diesel engine, common rail injectors have their own benefits, especially when it comes to emissions regulations. 

The main benefits of common rail are fuel efficiency, power, and emissions. Fuel efficiency and emissions go hand in  hand. You have a lot of micro bursts at specific times that create more power, more fuel efficiency, and less emissions. 

Power might be one of the best benefits of the common rail fuel injection system. The more pressure, the cleaner it's going to be, and the more power you're going to get out of it, especially versus conventional injectors. You might get away with a little more with conventional injectors, as far as using dirtier fuel, but you're never going to get the power that you will out of a common rail injector.


So, if you're curious about common rail fuel injectors and whether they're right for your diesel engine, Highway & Heavy Parts can help!


In the market for new injectors? Our ASE Certified Technicians are ready to help you find what you need for your diesel engine! Give us a call at 844-304-7688, or request a quote online!