Volkswagen Golf/Jetta 2 manual

Overrun cut-off and full throttle enrichment - testing
Fuel and exhaust systems - Digifant fuel injection / Overrun cut-off and full throttle enrichment - testing

1 Run the engine until the oil temperature is at least 80°C (normal operating temperature) then let the engine idle.

2 Manually close the full throttle valve switch 2 and hold it closed.

3 Open the throttle until the engine speed is approximately 2000 rpm. Check that the engine speed surges, indicating that the overrun cut-off is functioning.

4 If the engine does not surge, disconnect the wiring from the temperature sender and connect a bridging wire between the two contacts on the plug.

5 Repeat the procedure in paragraphs 2 and 3. If the engine now surges, the temperature sender is proved faulty. However, if it still refuses to surge, check the associated wiring and throttle valve switch 2.

6 If no fault is found, renew the control unit.

© 2019 All Rights Reserved.