Electronic Timing Advance - Scirocco 16V
Electronic Timing Advance - Scirocco 16VChecking RPM Dependant Timing Advance
1. Start the engine and let it idle for a few minutes to establish a base timing value in the control unit. Check this base reading with a timing light.
2. Disconnect the vacuum hose from the knock sensor control unit.
3. Raise the engine rpm and check the maximum advance.
Engine HT 14° @ 4300 rpm
Engine RD 16° @ 3000 rpm
Engine PL (16v) 13° @ 2500 rpm
CIS-E rpm-dependent timing advance:
- total timing @ 2500 rpm = measured base timing value (4° to 8° BTDC) plus approximately 13°
Note: On HT engines, if the timing advance is not within specification, disconnect the harness plug from the knock sensor control unit and check for continuity between terminal 11 and ground. Repair wiring as necessary and retest timing advance.
Checking Vacuum Dependant Timing Advance
Check the vacuum advance only after determining that the rpm dependent timing advance is correct.
1. Start the engine and increase the speed to approx. 3400 rpm.
2. Record the timing advance and let the engine return to idle.
3. Remove the vacuum advance hose from the knock sensor control unit.
4. Recheck the timing advance at 3400 rpm.
5. The timing should advance approx. 6° more with the vacuum hose disconnected.
6. If the timing advance is not within specification, check the vacuum hose for kinks, blockages, or leaks, and repair as necessary.
7. If the vacuum hose is not at fault, the knock sensor control unit may be faulty.