Checking for injectors sticking open (piezo injectors) — AUDI

🧭 Before you start

Fits: Audi A8 D3 (4E, 2002–2010)

• Renewed: faulty injectors

Don't miss

• Illustration shows cylinder bank 1.
• Lubricate all seals with engine oil or assembly oil before installing.
• Run engine at idling speed for several minutes (do not press accelerator) and then switch off. Fuel system will bleed itself automatically.
• If there is any air left in the fuel system, the engine may switch to the backup mode ('emergency running' mode) during the road test. Switch off the engine and erase the event memory. Then continue the road test.

🔧 Engine codes this applies to

📐 20 workshop diagrams for ASB

Real factory drawings for this job — timing marks, bolt locations and routing. Locked in the free view.

📋 Procedure

1. Pull off engine cover panel .
2. Clean all fuel rail connections with engine cleaner or brake cleaner and dry.
3. ⚠ Always read instructions on when working on injectors.Follow these instructions before starting work and while working on the fuel system. — Disconnect fuel return hoses from injectors; to do so, press down both tabs and at the same time pull centre piece up to release connection (arrow). [Note: Illustration shows cylinder bank 1.]
4. Connect adapter to return line connection of injector to be tested after adapter has been cleaned and blown out.
5. Generate a vacuum of -500 mbar using the hand vacuum pumpVAS 6213.

6. Renew faulty injectors .
7. Check O-ring for fuel return line connection for damage and deformation. [Note: Lubricate all seals with engine oil or assembly oil before installing.]
8. Press the return lines firmly onto the injectors from above so that they engage audibly on each injector. Then re-fit the retaining clips. Check that the return lines are seated securely by pulling them by hand from above.
9. Run engine at idling speed for several minutes (do not press accelerator) and then switch off. Fuel system will bleed itself automatically.
10. Check the entire fuel system for leaks.
11. After completing the repair, road-test the vehicle. Accelerate with full throttle at least once. Then check the high-pressure section of the fuel system again for leaks. [Note: If there is any air left in the fuel system, the engine may switch to the backup mode ('emergency running' mode) during the road test. Switch off the engine and erase the event memory. Then continue the road test.]
12. Install engine cover panel .

Other AUDI procedures

• Renewing camshaft oil seal – Audi · 1 torque figures
• Removing and installing vacuum pump – Audi A8 D3 · 2 torque figures
• Removing and installing coolant pipe (rear) – Audi A8 D3
• Removing and installing camshafts - cylinder head (left-side)
• Removing and installing flywheel · 3 torque figures
• Removing and installing toothed belt – Audi · 56 torque figures
• Removing engine – Audi A8 D3 · 41 torque figures
• Removing camshaft timing chain from camshafts – Audi A6/A7 C7 · 38 torque figures
• Installing engine – Audi A8 D4 · 36 torque figures
• Removing and installing camshaft timing chain · 29 torque figures