I've found some info in the MK1 Bentley on the Scorcco 16v. However it only talks about CIS-E, but the 'knock sensor control unit' is very similar to our 16v ignition controller, its basically the same but with knock sensing added on. However that doesnt mean the ign settings are the same, but I would be surprised if they arn't!
RPM-dependant Timing Advance
Start the engine and let it idie for a few minutes to establish a base timing value in the knock sensor control unit. Check and record this base reading. Disconnect the vacuum hose from the knock sensor control unit. Raise engine rpm as indicated, then compare maximum timing advance with the base value:
CIS-E rpm-dependant timing advance:
total timing @ 2500 rpm = measured base timing value {4 to 8 degrees BTDC} plus aproximately 13 degrees
After this check, stop the engine and reconnect the vacuum hose to the knock sensor control unit, if timing does not advance at increased rpm as specified, the knock sensor or the control unit is at fault. See 5, Knock Sensor System.
Vacuum Advance
Check vacuun advance only after determining that the rpm-dependent timing advance is correct. Start the engine and increase engine speed to about 3400 rpm. Record the total timing. Disconnect the vacuum hose from the knock sensor control unit and again raise the engine speed to about 3400 rpm. Timing should advance approximately 6 degrees from the previous value. If not, check the vacuum hose for kinks or leaks. If the hose is OK, the knock sensor control unit may be faulty.
