System pressure, checking
WARNING: This page is about a different variant/trim than selected.
- Remove engine cover.
- Briefly open fuel filler cap (pressure release).
CAUTION:
- Work on the fuel system may only be performed when the engine is cold!
- Fuel system is under pressure! Before loosening hose connections or opening the test connection (for fuel pressure testing), place rags around the connection area. Then release pressure by carefully loosening the connection.
- Open fuel supply line connection and absorb exiting fuel using a rag.
- Install pressure gauge V.A.G 1318 to fuel supply line.
- Open shut-off tap on pressure gauge. Lever points in direction of flow.
- Start engine and run at idle speed.
- Measure fuel pressure.
Specification: approx. 4.0 bar positive pressure
- Switch ignition off.
- Check for proper seal and residual pressure by observing pressure drop on pressure gauge.
After 10 minutes there must be a residual pressure of at least 2.5 bar.
If the residual pressure drops below 2.5 bar:
- Start engine and run at idle speed.
- Wait until pressure has risen, then switch off ignition. At same time, close pressure gauge pressure gauge V.A.G 1318 shut-off tap (lever at right angle to direction of flow) - arrow -.
- Observe pressure drop on gauge.
If the pressure now does not drop:
- Check pressure gauge for leaks.
- Check line connections and fuel injectors for leaks.
If the pressure drops again:
- Check pressure regulator in fuel filter. Fuel pressure regulator, checking