What fuel pressure should be at a common rail?
2,000 BAR – 29,000 PSI
Common rail direct fuel injection is a direct fuel injection system for petrol and diesel engines. On diesel engines, it features a high-pressure (2,000 BAR – 29,000 PSI) fuel rail feeding individual solenoid valves, as opposed to a low-pressure fuel pump feeding unit injectors or pump nozzles.
Is common rail more efficient?
The main advantages of the common rail direct fuel injection can be summarized in reduction of exhaust and noise emissions, better fuel efficiency and improved overall engine performance.
What should diesel rail pressure?
The pressure to deliver fuel from the high pressure pump to the rail/injectors at cranking is around 200 bars, at idle the pressure should be around 300 bars. When the vehicle is running the pressure ranges from 1200 bar to 2000 bar.
How does a common rail fuel system work?
HOW DOES THE COMMON RAIL SYSTEM WORK? The high pressure pump pressurizes the fuel and transfers it to the rail, a common conduit that serve as pressure accumulator and reservoir. The pressure is regulated by an electronically controlled valve, so that the rail maintains the correct pressure required by the ECU.
What pressure do fuel injectors run?
The Effect of Fuel Pressure on Injector Flow Rate Most injectors are flow rated at 43.5 psi. (Motorcraft rates their injectors at 39.15 psi.) If you are running a different pressure, your actual flow rate will be different than the advertised rate.
What replaced common rail?
The common rail diesel engine is certainly an advancement in diesel technology that will eventually replace the traditional direct injection system altogether. Perhaps when this new technology becomes more common in every diesel-powered vehicle, then it will become less expensive.
What are common rail injectors?
Common rail direct fuel injection is a direct fuel injection system built around a high-pressure (over 2,000 bar or 200 MPa or 29,000 psi) fuel rail feeding solenoid valves, as opposed to a low-pressure fuel pump feeding unit injectors (or pump nozzles).
What type of injectors are used in a common rail fuel injection system?
Common rail systems can use one of several injector designs: servo controlled electrohydraulic injectors, servo controlled electrohydraulic injectors incorporating pressure amplification, or. direct acting injectors.
How are the injectors activated in a modern common rail fuel injection system?
Explanation: The fuel injectors present in the modern common rail fuel system are activated by the solenoid valve. Solenoid valves and the fuel pump are electronically controlled. Thus, the common rail serves as the high-pressure reservoir independent of the engine speed.
How does Bosch common rail fuel injection work?
The common-rail system with pressure-compensated solenoid injectors by Bosch enables the flexible injection of fuel at pressures up to 2,500 bar. The “Digital Rate Shaping” strategy (DRS) contributes to a very small delay between pre-injection and main injection.
How do you control the pressure in a common rail?
Abstract: There are several approaches to control the pressure in the common rail. One early approach method was to supply more fuel than is needed to the common rail and use a pressure control valve to spill the excess fuel back to the fuel tank.
What is an example of a common rail fuel pump?
Example applications of this approach include the HP0 pump by Denso and the prototype common rail unit pump discussed in the paper on common rail components. In the Denso HP0 pump, a poppet-type solenoid valve is held open during a portion of the pump’s compression stroke to vary the amount of fuel compressed to high pressure.
Why is rail pressure control with a PCV fast?
Rail pressure control with a PCV is inherently fast because of the proximity of the system input (PCV) and system output (rail pressure sensor). In other words, the system does not include the delay resulting from fuel passing through the high pressure pump as would be the case for some of the pump metering approaches.