Touareg V8-4.2L (BAR) (2007)
Fuel Pressure Release: Service and Repair
Releasing Pressure on High Pressure Side
CAUTION!
The fuel injection system is divided into a high pressure side (maximum approximately 120 bar) and a low pressure side (approximately 6
bar).
Before opening the high pressure side, e.g. removing high pressure pump, fuel rail, injectors, fuel pipe or fuel metering valve (N290) or
fuel metering valve 2 (N402), the fuel pressure on the high pressure side must be reduced to a residual pressure of 6 bar. The procedure
for this is as follows:
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Disconnect connector from the fuel metering valve (N290) on the right side of the high pressure pump - arrow -.
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Then disconnect connector from the fuel metering valve 2 (N402) on the left side of the high pressure pump - arrow -.
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Allow engine to idle approximately 10 seconds.
‹› If the fuel metering valve electrical connectors are disconnected in idle, the pressure on the high pressure side drops to approximately 6 bar.
‹› After the high pressure has been released, the high pressure system must be opened immediately. Otherwise, the pressure increases again due to
the warming of the fuel.
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Switch off ignition.
CAUTION!
Fuel lines are pressurized! Wear protective goggles and protective clothing to prevent injuries and contact with skin. Before opening the
high pressure system, place a cloth around the connection.