Note: After replacing the fuel rail, the intake manifold flap potentiometer "G336" must be adapted to the engine control unit "J623".
Remove the engine casing. Unscrew the "arrow" screws securing the coolant pipeline to the intake manifold. Remove the air filter housing.
Unscrew the screws "arrow" on the left and right. Disconnect the lower part of the air duct "1" from the fasteners and remove. Remove the noise-insulating casing.
Release coolant hose "3". Disconnect connector "1" on boost pressure sensor "G31". Unscrew screws "arrows". Loosen clamp "2" of air duct hose and remove air duct hose from throttle valve unit "J338" by moving downwards.
Disconnect the following connectors.
1. From FSI injectors
2. From the knock sensor 1-G61-
4. From the intake manifold flap valve "N316", fuel pressure sensor G247-, intake manifold flap potentiometer "G336", coolant temperature sensor "G62", Hall sensor "G40"
Caution! The fuel system is under pressure! Before opening the high-pressure circuit of the injection system, the fuel pressure must be released to residual pressure.
Disconnect the fuel supply line "1" from the intake manifold. Remove connector "3" from the bracket. Disconnect connectors -4, 5 and 6-. Disconnect the wiring harness from the fuel rail.
Disconnect the connector from the intake manifold flap valve "N316" "2". Disconnect the vacuum lines of the "arrow" 6t valve of the intake manifold flap "N316" "2" and from the air filter housing.
Unscrew screw "1" and push the air duct to the left.
Unscrew the high-pressure fuel line fixing clamp "arrow". Unscrew the union nuts of the high-pressure fuel line on the high-pressure pump and on the fuel rail. Remove the high-pressure line.
Note: There must be no increased pressure in the fuel system. Collect any leaking fuel with a clean rag. Close open fittings with clean protective caps. Make sure that no dirt gets into the fuel system.
Slightly loosen the fastening nut "3" and completely unscrew the screw "1".
Disconnect connector "1" from the intake manifold flap potentiometer "G336". Unscrew the intake manifold screws.
Slightly pull the intake manifold off the cylinder head and unscrew the connector bracket "arrow".
Note: Cover the intake ports with a clean cloth.
Installation
Screw the connector bracket back on. Push the intake manifold over the threaded studs (left and right below) on the cylinder head. Installation in reverse order.