Fuel Pressure

Fuel Pressure

Test Sequence
Read safety precautions before beginning work.
- Observe the rules for cleanliness.

CAUTION: Fuel supply line is under pressure. Wear protective goggles and protective clothing to prevent injuries and contact with skin. Before removing from hose connection wrap a cloth around the connection. Then release pressure by carefully pulling hose off connection.







- Disconnect the supply line - arrow - and collect the escaping fuel with a cloth.

NOTE: Press in securing ring to disengage the fuel line.







- Install the fuel injector pressure gauge V.A.G 1318 with the adapter set V.A.G 1318/17A.
- Open shut-off valve of pressure gauge set.
- Switch ignition on often until fuel pressure on pressure gauge no longer rises.
- Read off fuel pressure on pressure gauge. Specified value: 4.0 to 6.0 bar.

If fuel pressure is OK, check retaining pressure. Residual Pressure

If the Specification is Exceeded
- If the fuel filter pressure relief valve is faulty, replace the flange and the fuel filter:

If the Specification is Not Obtained
- Check the fuel lines for possible restrictions (kinks) or blockages.

If no malfunction can be found:
- Replace flange with fuel filter and pressure relief valve:
- Repeat the test.

If specified value is again not obtained:
- Fuel Pump (FP) faulty, replace fuel delivery unit.