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  Vacuum Pipes

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Engine Data 2.0 8V
Engine Data 2.0 16V
Engine Data 2.3 16v
Engine Data 2.9 12V
Engine Data 2.9 24v
Engine Data 2.5 TD
Ford-Cosworth 24V
2.3 Engine Overview
A4LDE Auto Box
MT75 Manual Box
Vacuum Pipes
Wiring Loom Diagrams

Vacuum Pipe Connections
The underbonnet layout especially on the 24V can be rather daunting with a multitude of strange looking valves and vacuum controls for the various systems.

Primarily there are 3 major systems that use vacuum control.

The Variable Inlet System that is used to increase engine power at certain revs and loads - this uses a vacuum solenoid to apply vacuum to a mechanical valve located at the front of the inlet manifolds under the control of the EECV.

The EGR system that uses vacuum to open a valve between the exhaust manifold and the inlet manifold to allow exhaust gas to be drawn into the engine to reduce the size of the fuel/air mixture when running under light loads which increases fuel efficiency and reduces harmful exhaust emissions.

Closed circuit EVAP system which retains fuel vapours within the engine system preventing the harmful release of petrol vapours into the atmosphere.

The vents inside the air-conditioning evaporator are also controlled using a vacuum connection.

The diagrams showing the correct connections of the various pipes are shown below for the 2.9 24V engine.

Vacuum Pipes

EGR system (24V)




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