[Paulporsche]

There is no factory baseline setting or starting point per se for the idle and mixture screws, as David has said.

However, you need to make sure that the metering plate at rest is set correctly, ie its top surface is even with the part of the cone where it changes from sloped to vertical. The you can adjust from there with the mixture screw. That should get you started.

Joe Engineer on Youtube recently produced a test in which he felt that a good start point was to set the mixture screw to the point where the injectors just start to flow fuel. This would be another way to get started.

There is also a field test on this forum developed by poster Souk in which he raises and lowers the metering plate while running and sees whether the revs rise or fall. Check that out. It will probably also get you started.

You could even try, once idling, revving the engine and quickly snapping off the throttle and observing what happens. If the revs stay up you are probably too lean. If the engine wants to stall by quickly dropping or if the revs rise and fall rhythmically, then probably too rich.

Any of these methods will probably get you in the ballpark for further tuning.

Later you can check mixture with an A/F meter or, as I understand on Lambda controlled cars, with a dwell meter. FYI, re the dwell method, I am not positive since I have no O2 sensor on my car.

When doing CIS work, always make sure all the ignition components are working correctly first.