The development of diesel engines is currently very rapid. In the past, diesel engines relied on carburetors as their engine system. However, now they rely on a common rail system. 

So what is the function of the latest system used in these diesel engines? And how does it work? For more details, please pay attention to the following review. 

Function of Common Rail

Common rail is a fuel system used in diesel engines today, replacing the previous conventional systems like carburetors. 

Common rail itself has several important functions for diesel engines. The complete functions are as follows.

1. Supplying fuel

Common rail has a primary function, which is to supply fuel to diesel engine vehicles. As is known, cars cannot operate if they do not receive a sufficient fuel supply. During the fuel filling process in the car, the common rail will store the fuel in the fuel tank. Then, the fuel will be channeled to the engine to start the combustion process when the car engine operates.

2. Providing pressure to the fuel 

In addition to supplying fuel, common rail functions as a provider of pressure to the fuel. As is known, fuel that has been stored in the fuel tank cannot be released or injected immediately, so a certain amount of pressure is needed for the fuel to be channeled to the car engine. 

To achieve the appropriate fuel pressure, the common rail will command the high-pressure pump to apply pressure to the fuel so that it can exceed the high-pressure standard in the accumulator. This way, the fuel can be channeled to the combustion chamber. 

3. Distributing fuel thoroughly 

Common rail also functions to distribute high-pressure fuel through the rail pipes thoroughly to every part of the engine cylinder so that the car can operate normally.

4. Controlling the fuel injection timing system 

The fuel injection process in the engine cannot be done arbitrarily and must be based on the right duration and timing. To achieve this, the common rail is equipped with EDC (Electronic Diesel Control) which functions to control the timing and capacity of the fuel to be injected into the combustion chamber by the injector. 

5. Reducing exhaust emissions 

Common rail also functions to reduce exhaust emissions because the common rail system makes the combustion process in the combustion chamber more efficient, thereby minimizing the levels of nitrogen oxides (NOx), carbon dioxide (CO2), and diesel particulates. 

How Common Rail Works 

At a glance, the way common rail works in diesel engines is very similar to the working system of EFI (Electronic Fuel Injection) in gasoline engine vehicles. 

In conventional diesel engines, the fuel injected into the combustion chamber does not always have high or consistent pressure. This happens because when delivering fuel, conventional diesel engines use fuel pipes with varying injection pressures. 

In contrast, in the common rail system, fuel is stored in a "rail" that serves as a high-pressure fuel storage tank with stable pressure. When the engine requires fuel, the injection valve will automatically open, allowing fuel to enter the combustion chamber with stable pressure, without worrying about fluctuating pressure levels. This makes the combustion process in the combustion chamber more efficient, resulting in reduced exhaust emissions. 

Considering the common rail's functions are very important, vehicle owners are required to regularly and periodically check the condition of this system. If the vehicle shows symptoms such as difficulty starting the engine or experiencing misfire, immediately service it at the official Daihatsu workshop as this indicates a problem with the common rail system.