Fuel injection system (VW Tiguan 1)

General instructions for working with the injection system

The engine control unit "J623" is equipped with a self-diagnosis function. Before repairs, as well as for troubleshooting, the fault memory should be interrogated first. It is also necessary to check the vacuum hoses and connections (air suction through leaks). Fuel hoses may only be secured in the engine compartment using spring clamps. The use of clamps or screw clamps is not permitted. A minimum voltage of 11.5 V is required to maintain the proper operation of electrical components. Do not use silicone sealant. Silicone particles sucked into the engine do not burn and cause the lambda probes to fail. The vehicle is equipped with a collision fuel shut-off system. By shutting off (via the corresponding relay) fuel pump, it reduces the likelihood of the car catching fire after a collision. In addition, this system allows you to reduce the time needed to start the engine, thereby increasing the convenience of using the car. When opening the door, the fuel pump is turned on for 2 seconds, which allows you to create the necessary operating pressure in the fuel system in advance.

Intake manifold

• 1 - Intake air temperature sensor 3 "G520" with intake manifold pressure sensor 3 "G583"
• 2 - 5 Nm
• 3 - 7 Nm, self-tapping screw. Tightening the fastening screw with a screwdriver is only permitted if the screwdriver rotation speed does not exceed 500 rpm and the tightening torque is set to no more than 7 Nm
• 4 - Suction pipe
• 5 - O-ring, replace
• 6 - Control unit for regulating flap "J808". The control unit for regulating flap with plastic housing does not need to be adapted to engine control unit "J623". When replacing, delete the adaptation parameters in the memory and re-adapt engine control unit "J623"
• 7 - 7 Nm, self-tapping screw
• 3 - Suction pipe
• 9 - Intake manifold pipe
• 10 - 7 Nm, self-tapping screw
• 11 - 5 Nm
• 12 - Intake manifold pressure sensor "G71"
• 13 - O-ring, replace
• 14 - Intake manifold, For removal - removal and installation of the control unit of the regulating valve "J808" and the control unit of the throttle valve "J338"
• 15 - 20 Nm
• 1B - Fuel pressure sensor "G247", 22 Nm, check fuel pressure in the high pressure area
• 17 - 80 Nm
• 18 - Lower part of the intake manifold. For removal - removal and installation of the control unit of the regulating valve "J80B" and the control unit of the throttle valve "J338" and the intake manifold
• 19 - Gasket, replace, observe installation position
• 20 - 20 Nm
• 21 - Air flap unit "J338". When replacing, delete the adaptation parameters in the memory and re-adapt the engine control unit "462322" 7 Nm
• 23 - Pressure pipe from turbocharger
• 24 - Mounting bracket
• 25 - 7 Nm

• 1 - Fuel supply line connection
• 2 - Fuel hose for fuel supply line. Low pressure. To high pressure fuel pump
• 3 - Fastening clamp
• 4 - Connecting hose to electromagnetic valve 1 of the absorber "N80"
• 5 - Solenoid valve 1 of the activated carbon absorber "N80"
• 6 - Connecting hose
• 7 - To the pressure pipe
• 8 - Connecting tube
• 9 - Connecting hose to the intake manifold pipe
• 10 - 8 Nm
• 11 - Fuel pipe. High pressure. Tightening torque of union nuts: 18 Nm
• 12 - Branch pipe to suction branch
• 13 - Connecting hose
• 14 - Crankcase ventilation system check valve
• 15 - Connecting hose
• 16 - Boost pressure limiting solenoid valve "N75"
• 17 - Connecting hose
• 18 - Connecting hose to turbocharger
• 19 - Branch pipe
• 20 - 5 Nm
• 21 - Connecting hose to turbocharger
• 22 - Branch pipe
• 23 - Crankcase ventilation system pipe
• 24 - Connecting hose of the crankcase ventilation system
• 25 - Connecting hose, to the turbocharger pressure limiting solenoid valve "N75"
• 26 - Crankcase ventilation system pipe, connects to the cover of the distributing mechanism

Fuel rail with injectors

• 1 - O-ring, replace, lightly lubricate with clean engine oil before installation
• 2 - Elastic element, after each removal replace the lower part of the intake manifold, pay attention to the correct fastening on the injector
• 3 - Cylinder 4 injector "N33". Cylinder 1 injector "N30". Cylinder 2 injector "N31". Cylinder 3 injector "N32". With a Teflon sealing ring and support washer, after removing the injector, the Teflon sealing ring and support washer must be replaced
• 4 - Lower part of the intake manifold. For removal - removal and installation of the control unit of the regulating valve "J808" and the control unit of the throttle valve %)338-and intake manifold

Air filter

• 1 - 1.6 Nm
• 2 - Upper part of the air filter
• 3 - Vacuum hose. Do not use tools with sharp edges to remove the hoses to avoid damage to the pipe and vacuum hose, replace if damaged. From the camshaft housing
• 4 - Spring clamp
• 5 - Air intake sleeve
• 6 - Overlay
• 7 - Intake air duct
• 8 - Lower air filter with captive mounting bolt, tightening torque: 8 Nm. With suction pipe
• 9 - Water drain pipe. When installing, the arrows on the bottom of the air filter and on the water drain pipe should be located opposite each other
• 10 - O-ring, replace
• 11 - Filter element

High pressure pump

• 1 - Roller tappet, lightly lubricate with engine oil when installing
• 2 - O-ring, replace, lightly lubricate with engine oil when installing
• 3 - High pressure pump with fuel pressure regulating valve "N₂76"
• 4 - 20 Nm, tighten bolts evenly
• 5 - Pipe. High pressure
• 6 - Union nut, 18 Nm. Strictly observe safety regulations, hold the connecting pipe at the high-pressure pump when unscrewing
• 7 - Fuel hose. Low pressure. With spring clamp
• 8 - Pipe. Low pressure