What is common rail injection?
A common rail engine is designed to supply constant fuel pressure to electronically controlled injectors through a shared fuel reservoir. This means that the fuel supply is not dependent on the engine revs. A common rail system is built around four basic components:
- A high pressure pump with pressure regulator and inlet metering valve.
- A rail which contains a pressurised reserve of fuel.
- Injectors which inject precise amounts of fuel into the combustion chamber as required.
- A Diesel Control Unit – the 'brain' of the system, which precisely controls injector flow and timing as well as rail pressure while continuously monitoring the operating conditions of the engine.
Benefits of Common Rail:
- Accommodates all planned emissions legislation
- Opportunity for pre-injection and post-injection
- Modular system
- Full electronic control
- Fuel Economy
- Enhanced reliability and performance
- Cover's a variety of vehicle applications.
Common Rail systems are already fitted to many Ford, Renault, Kia and Hyundai vehicles and many new applications are planned for the near future.
The spare part proposal for each system includes:
- HP Pump with Venturi and Inlet Metering Valve
- The Rail with Rail Pressure Sensor
- The injector
- The tube
- The Filter
- The Electronic Control Unit (ECU)
Delphi, as a world leader in diesel, have been involved in the development of Common Rail technology from the beginning. Some of the first systems were pioneered by Lucas Diesel Systems and Delphi have inherited this expertise.
Common Rail marks a fundamental change in diesel technology and is happening now.
More and more vehicles are being introduced with Common Rail systems. It is calculated that in 2004, 70% of new diesel vehicles incorporated Common Rail injection systems and over 5 million such systems are already on the road.