Removing and installing fuel pressure regulating valve N 276 — VW

Removing and installing
fuel pressure regulating valve
N 276
Special tools and workshop equipment required
Torque wrench
Open-end spanner insert, 36 mm
Fuel pressure regulating valve
N 276
6
is located on high-pressure accumulator.
It ensures constant pressure in the high pressure accumulator and in injector lines.
If pressure is too high in the fuel high-pressure circuit,
fuel pressure regulating valve
N 276
opens.
As a result a small amount of fuel from the high-pressure accumulator will make its way back to fuel tank via the return line.
If pressure is too low in fuel high-pressure circuit,
fuel pressure regulating valve
N 276
closes.
This seals the high-pressure side against the low-pressure side.
Note
The
fuel pressure regulating valve
N 276
cannot be re-used.
Caution
After renewing high-pressure pump,
fuel pressure regulating valve
N276
or fuel delivery unit, it is essential to reset learnt values of respective components. Use Guided functions and start
»Basic settings; Resetting learnt values«
on
Vehicle diagnostic tester
, for this. Otherwise there will be problems in starting the engine.
Removing
WARNING
Always observe rules for cleanliness and instructions when working on fuel system
Chapter
.
Always follow these rules for cleanliness and instructions before starting work and while working on the fuel system.
Remove engine cover panel
Chapter
.
Removing high-pressure accumulator
Chapter
.
Clean threaded area around
fuel pressure regulating valve
N 276
(e.g. with standard cleaning solution) before removing.
There should be no dirt in the hole on the high-pressure accumulator element (high-pressure accumulator) under any circumstances.
Note
Clean carefully; cleaning solvent must not enter the electrical connector.
Dry
fuel pressure regulating valve
N 276
.
Slacken union nut (counterhold at hexagonal flats on housing). Then unscrew and remove by hand.
Extract dirt from threads and sealing surfaces. Do not use tools or other instruments for this purpose.
Note
Seal off drilling immediately with a suitable plug to prevent dirt from entering.
Installing
Note
The
fuel pressure regulating valve
N 276
has a deformable sealing lip and no separate seal; it can therefore be used only once.
Check that sealing surfaces (deformable sealing lip) and threads on new
fuel pressure regulating valve
N 276
are not damaged.
Check sealing surface of drilling.
Lubricate thread and deformable sealing lip of
fuel pressure regulating valve
N 276
with Molybdenum grease.
Screw on union nut by hand.
Align new regulating valve so that the connecting line is free of tension after connector is attached.
Hold regulating valve in this position with an open-end spanner on housing hexagon or use for example multi slip-joint pliers for this.
To tighten union nut, use a suitable torque wrench with a 36 mm open-end spanner insert.
Install high-pressure accumulator
Chapter
.
Specified torque settings:
Chapter
.
Check fuel system for leaks.
Connect
vehicle diagnosis tester
.
Read event memory and erase stored event entry if necessary.
After installation, run engine at moderate speed for several minutes and then switch off.
Then test drive the vehicle, accelerating to full throttle at least once.
Then check high-pressure part of fuel system again for leakage.
Read event memory again.