911 SC Cabriolet F6-2994cc 3.0L SOHC (1983)
7. Guide in Special Tool P 377.
8. Turning tool clockwise = richer mixture.
Turning tool counterclockwise = leaner mixture.
Note: The following points are important.
a) Always adjust CO level from lean to rich.
Example: If mixture is too rich, first turn idle control screw counterclockwise further than necessary and then clockwise to specified value.
b) Never exert force on special tool during adjustments (engine dies).
c) Turn control screw only very slightly, since even a slight turn will change CO content in exhaust gas considerably.
9. Remove special tool.
10. Accelerate engine briefly.
11. Wait until CO tester shows exhaust gas concentration at idle speed.
Specification: 0.6 ± 0.2 % CO @ 900 ± 50 RPM
12. Recheck idle speed and, if necessary, correct.
13. After finishing adjustments screw a new shear-off screw in access bore and tighten until screw shears off. Reconnect oxygen sensor plug.
14. Coat threads of cap nut for test connection on catalytic converter with Bosch VS 140 16 Ft or optimoly HT grease.
