How does a common rail injector works?

How does a common rail injector works?

Abstract: In the common rail system, fuel is distributed to the injectors from a high pressure accumulator, called the rail. The rail is fed by a high pressure fuel pump. The pressure in the rail, as well as the start and end of the signal that activates the injector for each cylinder are electronically controlled.

How does a common rail pressure sensor work?

It is a part of vehicle’s fuel system and designed to monitor the fuel pressure that is present at the fuel rail. The sensor sends this signal to the ECU, which then uses it to make adjustments to the vehicle’s fuel and timing. When the sensor has an issue it can cause problems with the performance of the vehicle.

What is common rail injection system?

Common rail is a fuel injection system found in modern diesel engines. Common rail systems provide a level of flexibility which can be exploited for class leading emission control, power and fuel consumption.

What is the working principle of fuel injector?

Working principle of a conventional fuel injector: It lifts off its seat while spraying the diesel into the cylinder in highly atomized or mist form. The moment the pressure drops, the needle valve comes back to its seat, which causes the injection to stop. The injection nozzle has extremely critical tolerances.

What is the fuel pressure in the common rail?

29,000 psi
In common rail systems, a high-pressure pump stores a reservoir of fuel at high pressure — up to and above 2,000 bars (200 MPa; 29,000 psi).

How does a common rail high pressure pump work?

At engine start and for preheating the fuel when temperatures are low, the rail pressure is controlled by the PCV. To heat up the fuel quickly, the high-pressure pump delivers and compresses more fuel than is needed and the excess fuel is discharged by the PCV into the fuel return.

How do injector nozzles work?

Injector nozzles interact with Pistons in Combustion Chambers. When the Piston is drawn away from the Sparkplug, the Injector Nozzle sprays a fuel and air mixture into the Combustion Chamber. Injector Nozzles can be thought of as the “heart” of the engine.

How much pressure does a common rail diesel have?

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.

What are the common problems in common rail injection system?


  • Power loss
  • Rough idle
  • Engine rattle
  • Dirty diesel engine oil
  • Oil use
  • EGR valve problems
  • Inlet system deposits
  • Turbocharger failures
  • Excessive diesel particulate filter regenerations. CRD Fuel Enhancer will restore injectors and avoid common rail problems.
  • How does a common rail injector work?

    Pre-injection: Reduces “diesel knock” by injecting a small fuel quantity before the piston reaches the Top-Dead-Center (TDC).

  • Main injection: Happens just after the TDC. This is the main injection quantity. Sometimes it is split into two parts.
  • Post-injection: Controls emissions. It happens before the Bottom-Dead-Center (BDC).
  • How to repair Bosch common rail injectors?

    No fault code or fault code content has nothing to do with the injector;

  • The low pressure oil circuit is normal;
  • The rail pressure cannot reach 25MPa;
  • Disconnect the oil return pipe of the fuel injector and observe that the oil return is large;
  • Why does common rail fuel injectors fail?

    Common rail injector failure is usually sudden and will stop the engine for no apparent reason. The solenoid in the injector being the weakest part is usually the culprit, and can allow fuel to enter the cylinder unregulated. Often the injection pump cannot maintain fuel rail pressure and the engine will shut down due to the ECU fail safe program.