Residual Pressure

Residual Pressure

Test Conditions







- Fuel pressure OK and pressure gauge V.A.G 1318 connected. Checking fuel pressure.

Test Sequence
- 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.
- Watch pressure drop on gauge. After 10 minutes the pressure must not drop below a 3.0 bar decrease.

If the pressure drops further:
- Switch ignition on often until fuel pressure on pressure gauge no longer rises.







- Immediately close the pressure gauge - arrow - shut-off tap.

If The Pressure Drops Again
(Leak on engine side)
- Check the connections at the fuel rails and the high pressure pump for leaks.

If no malfunction can be found:
- Replace high pressure pump.

If Pressure No Longer Drops Now
(Leak on fuel tank side)
- Check fuel line to flange for leaks.

If no malfunctions are found on fuel line:
- If the non-return valve inside the flange with fuel filter is faulty, replace the flange and fuel filter.