Content .. 434 435 436 437 ..

Volkswagen Golf Variant / Jetta. Manual - part 436

take manifold.

– Remove the protective strip, if equipped -item 1-

⇒ Item 1 (page 312)

– Disconnect from the fuel injectors -A-, the Exhaust Pressure

Sensor 2 - G451- -B- and the Fuel Pressure Sensor - G247-

-C-.

– Remove the coolant line bolts -arrows- from the intake mani‐

fold and lay the line in front of the intake manifold.

– Unclip the wiring harness from the wiring guide for the glow

plugs.

Caution

Always follow the procedure »Glow Plug Connectors, Remov‐

ing and Installing«.

– Remove the glow plug connectors. Refer to

⇒ “1.3 Glow Plug Connectors, Removing and Installing”, page

410

– Remove the high pressure line -item 21-

⇒ Item 21 (page 314)

between the high pressure fuel pump

and rail element (high pressure reservoir).

– Remove the toothed belt sprocket from the high pressure fuel

pump.

– Hold the high pressure fuel pump hub with the Counterhold -

Camshaft Gear - T10051- and remove the nut -1-.

3. Diesel Direct Injection System

327

Pressure Pad - T40064/1- as shown and remove the hub from

the high pressure fuel pump. Counterhold with a 24 mm open-

end wrench if necessary.

– Remove the high pressure fuel pump bolts -arrows-.

– Remove the high pressure fuel pump.
Installing:
Install in reverse order of removal. Note the following:
• Make sure no contaminants enter the fuel system when in‐

stalling the high pressure fuel pump.

• Only remove the plugs right before installing the fuel lines.
• Do not change the angles of the high pressure lines
• Make sure the line connections are secure.
• Do not interchange the supply line and the return line.
– First tighten the union nuts for the high pressure lines by hand.
– Make sure the high pressure lines are seated without tension.

– Tighten the high pressure lines using the Torque Wrench 1331

5-50Nm - VAG1331- with Torque Wrench 1331 Insert - Re‐

versible Ratchet - VAG1331/1- and Union Nut Socket -

T40055- .

Tightening Specifications:
• Overview - Toothed Belt Drive. Refer to

⇒ “1.2 Overview - Toothed Belt Drive”, page 43

• Refer to

⇒ “3.3 Overview - Fuel System”, page 311

. Overview

- Fuel System

– Installing and tensioning the toothed belt. Refer to

⇒ “1.6 Toothed Belt, Removing, Installing and Tensioning”,

page 95

– Fill the fuel system. Refer to

⇒ “3.9 Fuel System, Filling/Bleeding”, page 328

3.9

Fuel System, Filling/Bleeding

Caution

After installing the high pressure pump, it must be filled with

fuel before starting the engine for the first time (never let the

pump run dry).

328

♦

When installing the high pressure pump, make sure that no

dirt enters the fuel system.

♦

Only remove the plugs right before installing the fuel lines.

♦

The fuel tank must be filled.

To Fill the High Pressure Fuel Pump with Fuel, Proceed as Fol‐

lows:
– Switch the ignition on.
– Connect the Vehicle Diagnostic Tester and perform the “Vent

Fuel system” Guided Function.

Note

The fuel pump are activated for 3 minutes.

– Then start the engine.
– After filling the fuel system, let the engine run at a moderate

speed for a few minutes and then switch it off.

– Check the fuel system for leaks.
– Scan the DTC memory and delete the DTC memory entry if

necessary.

– Test drive the vehicle for at least 20 km/h and test full-throttle

acceleration at least once. Then check the high pressure area

one more time for leaks.

Note

If there is still air in the fuel system, the engine may switch to

emergency mode during the road test. Turn off the engine and

erase the DTC memory. Then continue the road test.

– Scan the DTC memory again.

3.10

Fuel System, Performing Leak Test

DANGER!

♦ Follow the safety precautions when working on the diesel

direct fuel injection system. Refer to

⇒ “1 Safety Precautions when Working on Diesel Direct

Fuel Injection System”, page 303

♦ Pay attention to the guidelines for clean working condi‐

tions. Refer to

⇒ “2 Guidelines for Clean Working Conditions”,

page 305

Always pay attention to these instructions before and during

work.

Test Sequence
– Remove the engine cover. Refer to

⇒ “1.4 Engine Cover, Removing and Installing”, page 90

3. Diesel Direct Injection System

329

accelerator pedal and then stop the engine. The fuel system

bleeds itself.

– Check the entire fuel supply system for leaks.
If there are leaks despite correct tightening specifications, replace

the affected component.
– Perform a road test where the accelerator pedal is fully de‐

pressed at least one time. Then check the high pressure area

again for leaks.

Note

♦

Follow all applicable safety precautions during a road test.

Refer to

⇒ page 303

♦

If there is still air in the fuel system, the engine may switch to

emergency mode during the road test. Stop the engine and

delete all DTC entries. Refer to Vehicle Diagnostic Tester

“Guided Functions”.

– Install the engine cover. Refer to

⇒ “1.4 Engine Cover, Removing and Installing”, page 90

3.11

Pressure Retaining Valve in Fuel Re‐

turn, Checking

Function
The pressure retaining valve in the fuel return has the function of

always maintaining a residual pressure (control quantity) of ap‐

proximately 10 bar (145.03 psi).
The fuel injectors require this control quantity to function correctly.
Special tools and workshop equipment required
♦ Fuel Return System Tester - VAS6330- (not illustrated)
Test Sequence

DANGER!

♦ Follow the safety precautions when working on the diesel

direct fuel injection system. Refer to

⇒ “1 Safety Precautions when Working on Diesel Direct

Fuel Injection System”, page 303

♦ Pay attention to the guidelines for clean working condi‐

tions. Refer to

⇒ “2 Guidelines for Clean Working Conditions”,

page 305

Always pay attention to these instructions before and during

work.

– Remove the engine cover. Refer to