Manifold Vacuum Experiment

92b said
If I have this correct.
After replacing the vac adv. idle timing was at 30 deg. connected to manifold vacuum. 20 deg. at idle w/ out vac.
After turning the adjustment screw full clockwise Idle timing increased to 40 deg. and idle time w/out vac remained at 20 deg.
Your observations were that the engine idles cleaner by a good bit and the engine has more balls at part throttle pulling up inclines.
Separating the two observed results. First the cleaner idle. I think this can be attributed to using manifold vac.
The second result, "more balls at part throttle", can be attributed to the full clockwise adjustment and a working diaphragm in the new vacuum adv. This second result would have still been realized even if the vac adv. was connected to ported vac. only.
Looks like your combination benefited from the changes you made so far.
Good job testing and tuning. Thank you for sharing.

No, not quite. The change from 30 to 40 was me turning the distributor. lol I never took data with the adjusted "as it came", which was "about" half way between CW and CCW. The only data I took was after I turned the vacuum can all the way CW. This expands and "softens" the spring tension so that less vacuum is required to move the diapgragm.

I have to do one more thing to it today and that should get it all sorted out. In my efforts to try and lean it out at idle, (remember how I said it was rich at idle?) I put in some smaller idle fuel restrictors. I'm going to put the stock ones back in, because now I have a stumble immediately off idle and I know that's what's doing it.