Checking fuel pressure regulator and residual pressure: Audi TT Mk2 (BAT, BDW, BGU, BNK, …)

🧭 Before you start

Fits: Audi TT Mk2 (8J, 2006–2014)

• Special tools named: V.A.G 1318/17, V.A.G 1318/23

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• Disconnecting the electric fuel pump 2 relay J49 will prevent the fuel pump from being activated when the driver's door is opened.
• Use hose clips (arrows) to secure the auxiliary hose.
• Do not attach hose clamp3094 directly to fuel pipe – Danger of damage.
• Before removing the pressure tester, release the fuel pressure by opening the cut-off valve. Hold a container under the connection.
• Secure all hose connections with the correct type of hose clips (same as original equipment) Electronic parts catalogue.

🔧 Engine codes this applies to

📋 Procedure

1. Press the two clips in direction of the (arrows) and remove cover from electronics box in engine compartment.
2. Disconnect electric fuel pump 2 relay J49(item 2.1). [Note: Disconnecting the electric fuel pump 2 relay J49 will prevent the fuel pump from being activated when the driver's door is opened.]
3. ⚠ The fuel system is pressurised. Before opening the system place a clean cloth around the connection. Then release pressure by carefully loosening the connection. — Pull release ring and disconnect fuel supply line (arrow).
4. Detach fuel supply line (arrow) from fuel rail.
5. Connect the K-Jetronic testerV.A.G 1318 with adaptersV.A.G 1318/11, V.A.G 1318/17 and V.A.G 1318/23.

6. Connect pressure tester to fuel supply hose.
7. Connect a fuel-resistant auxiliary hose between fuel rail and tester. [Note: Use hose clips (arrows) to secure the auxiliary hose.]
8. Open cut-off valve on pressure tester.
9. Start the engine and run at idling speed.
10. Measure the fuel pressure.
11. Switch off ignition.
12. Check delivery rate of fuel pump Fuel supply system, petrol engines20Fuel pump.
13. Check leak-tightness and residual pressure by watching the drop in pressure on the pressure gauge.
14. Start the engine and run at idling speed.
15. Allow pressure to build up, then switch off ignition. At the same time close cut-off valve of K-Jetronic testerV.A.G 1318.
16. Observe pressure drop on pressure gauge.
17. Check pipe connections, injectors and O-rings on fuel rail for leaks.
18. Check pressure tester for leaks.
19. Open cut-off valve on pressure gauge (lever points in direction of flow).
20. Remove rear seat bench General body repairs, interior72Rear seats; Removing and installing seat bench/individual seats.
21. Unclip the retaining tabs (arrows) for the flange cover (right-side).
22. Press release tab and disconnect fuel return line (arrow).
23. Connect adapter1318/17-1 to fuel return line.
24. Clamp off adapter hose using hose clamp3094. [Note: Do not attach hose clamp3094 directly to fuel pipe – Danger of damage.]
25. Cover the return line connection with a cloth.
26. Start the engine and briefly run at idling speed.
27. Allow pressure to build up, then switch off ignition.
28. Observe pressure drop on pressure gauge.
29. Renew fuel pump Fuel supply system - petrol engines20Fuel delivery unit/fuel gauge senders; Removing and installing fuel delivery unit/fuel gauge senders.
30. Renew fuel filter with integrated fuel pressure regulator Fuel supply system, petrol engines20Fuel filter; Removing and installing fuel filter. [Note: Before removing the pressure tester, release the fuel pressure by opening the cut-off valve. Hold a container under the connection.]
31. Installation is carried out in the reverse order; note the following: [Note: Secure all hose connections with the correct type of hose clips (same as original equipment) Electronic parts catalogue.]
32. Fit electric fuel pump 2 relay J49(item 2.1) back into relay and fuse holder.
33. Install rear seat bench General body repairs, interior72Rear seats; Removing and installing seat bench/individual seats.

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