Vehicles with unit injector engine — AUDI
Vehicles with unit injector engine on Audi: factory workshop procedure for engines AGR, AHF, ALH, ASV. Full factory text, tools and checks.
Workshop procedure for AUDI — the factory write-up, straight from real workshop data.
📋 Procedure
ℹ️ Torque figures below come verbatim from workshop data — always cross-check against your vehicle's factory manual before final tightening.
AHF ALH ASV ASZ ATD AXR
Special tools and workshop equipment required
Hose clamps 3094
V.A.G 1274 with V.A.G 1274/2 A
V.A.G 1318/17-1
Test device for tandem pump VAS 5187
Leaks in the fuel system may result in the following:
Foam build-up or air bubbles in the supply pipe
Loss of power, misfiring
Starting problems
Work sequence
Pull out oil dipstick -1- from guide tube.
Remove engine cover -arrows-.
Re-insert oil dipstick into guide tube.
Warning
The fuel system is under pressure. Place a cloth over the connection before opening the system. Then open the connection carefully to relieve pressure.
In extreme cases the fuel pipes/hoses or the fuel can reach a temperature of 100 C on vehicles with unit injector engine. Allow the fuel to cool down before disconnecting the pipes/hoses - acute danger of scalding.
Wear protective gloves.
Wear protective goggles.
Remove plug -arrow-.
Note:
Illustration shows tandem pump with engine removed from vehicle.
Attach adapter 1274/2 to cooling system tester V.A.G 1274.
Connect adapter V.A.G 1274/2A to tandem pump using banjo bolt from VAS 5187.
Remove rear seat bench.
=> General body repairs, Interior; Repair group 72; Rear seats
General body repairs, Interior
Rear seats
Fold back floor covering under rear seat bench.
Detach cover for flange on fuel tank under rear seat bench (right side).
Press release tab and disconnect black fuel supply pipe -1-.
Note:
Do not disconnect fuel return pipe -2-.
Connect adapter hose V.A.G 1318/17-1 onto fuel supply pipe.
Clamp off adapter hose using hose clamp 3094.
Note:
The hose clamp 3094 must not be applied directly to the fuel pipe as this would cause damage.
Clamp off fuel return hose upstream of regulating valve using hose clamp 3094.
Use hand pump on tester to create a pressure of between 1.0 and 1.5 bar.
If the pressure constantly drops, locate leak and eliminate fault.
Notes:
After disconnecting the pressure tester, fit the plug and tighten to 25 Nm. Always replace seal.
To test the fuel return pipe, apply the hose clamp to the fuel supply hose at the fuel filter and connect the adapter hose 1318/17 to the fuel return connection.
TorqFix answers live for your specific car — tell it the engine code and it serves the matching sequence, torque figures and wiring for that exact variant.
Ask about my car →Other AUDI procedures
- Checking coolant temperature sender G62
- Checking intake manifold temperature sender G72
- Checking intake manifold pressure sender and elevation sender
- Connecting fault reader V.A.G 1551 and selecting engine electronic control unit
- Checking power supply to diesel direct-injection system
- 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
Who makes these pages, and how
TorqFix was built by a mechanic — after a 2,700 km drive with five roadside repairs that no diagnostic tool could explain.
The figures on this page come from manufacturer workshop documentation and are shown as they are. The page is assembled automatically from that data — it is not written by an AI. The AI works in the chat, where it answers for your specific car. It writes nothing here.
Variants of the same model differ. Cross-check torque against the factory manual for your engine before final tightening.
Seen a figure that does not match your manual? Write to us — we correct it and note when. support@torqfix.com
The story behind TorqFix →Workshop data on this page last updated 20 Sep 2026.