Fuel Delivery and Air Induction: Adjustments

ADJUSTMENT OF BASIC BOOST PRESSURE





IMPORTANT:
Basic boost pressure is the point of departure for the Trionic system's pressure regulating function and must therefore be adjusted to the correct level.

Continuous compensation of the maximum boost pressure in relation to the current basic boost pressure takes place through the system's adaptive function.

Increasing basic boost pressure above the specified value will not result in a higher boost pressure, as the adaptive function will adjust the maximum boost pressure down to the nominal value (negative adaptation).

When adjusting the length of the push rod it is important to place the pliers used to grip it as close to the threads as possible. Rotate the end piece carefully so that no burrs will be left on the push rod.

1. Undo the end piece's locknut and break the seal.
2. Remove the circlip and unhook the push rod from the boost pressure regulator's operating arm (the easiest way of performing the operation described in point 2 is from underneath).
Use special tool 83 94 538.
3. Adjust basic boost pressure by screwing the end piece in if basic boost pressure is too low or screwing the end piece out if basic boost pressure is too high.
Turning the end piece 1 complete revolution will change basic boost pressure by about 0.02 bar.

IMPORTANT: The boost pressure regulator must never be "pre-stressed" (tightened) by less than 2 mm (2 turns) even if basic boost pressure cannot be adjusted so that it lies within the tolerance limits of 0.40 ± 0.03 bar.





4. Connect the push rod to the operating arm and install the circlip.
5. Check the basic boost pressure on the road. Testing and Inspection
If basic boost pressure cannot be adjusted, check Boost Pressure Control Valve. Testing and Inspection
6. Seal the push rod.