How is the pressure in the common rail controlled?
Common Rail Injection System Pressure Control. 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 happens when the rail pressure is too low?
The Motor Control Module (MCM) monitors the rail pressure and when rail pressure deviation is greater than 200 bar for eight seconds, the MCM sets the code. This fault can occur due to the conditions listed below:
Why does the common rail injection system have a delay?
One important reason for this is that the system now includes a delay introduced by the high pressure pump. Metering the pump’s inlet flow will have the longest delay since the system delay includes the pump’s induction and discharge strokes; as a result, relatively higher rail pressure fluctuations can be generated [ Bosch 2007].
When to use Region 1 or Region 2 pressure control?
Region 1, distinguished by the slit-like opening and a low fuel flow rate change with valve stroke, is used to control the fuel flow rate to the pump during engine idling and low part load operation. Region 2, distinguished by the rapidly rising flow rate with increasing valve stroke, corresponds to mid-load up to full load operation of the engine.
Common Rail Injection System Pressure Control. 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.
One important reason for this is that the system now includes a delay introduced by the high pressure pump. Metering the pump’s inlet flow will have the longest delay since the system delay includes the pump’s induction and discharge strokes; as a result, relatively higher rail pressure fluctuations can be generated [ Bosch 2007].
How is rail pressure controlled on a Mercedes Benz?
Rail pressure is supposedly controlled by quantity control valve when warmed – saves power because the HP pump only pumps as much as needed – but I imagine it will have to tweak the pressure valve a bit to get best results. If the ‘problem’ is rough running, and you are not logging rail pressure deviation fault codes I would look elsewhere. hmm..
Region 1, distinguished by the slit-like opening and a low fuel flow rate change with valve stroke, is used to control the fuel flow rate to the pump during engine idling and low part load operation. Region 2, distinguished by the rapidly rising flow rate with increasing valve stroke, corresponds to mid-load up to full load operation of the engine.