Tom,
I just checked manifold vac & I'm sitting @ about 14in at idle. It drops w/ initial throttle, then increases a few inches, but sits less @ about 12-13in @ 2-2500rpms.
The odd thing is she's running good today; none of the "lumpa lumpa lumpa" miss from all day yesterday. I cleaned the ground strap earlier & tightend the new Vac hose on the MAP sensor, but that's all.
She has had one or two brief little fits where she was running like yesterday, but only for a few seconds then back to running fine with a blip of the throttle.
I had suspected the braided fabric vac hose that goes to the charcoal filter of possibly leaking, but it shows better than 15in @ idle.
I'm at a loss. Especially since today she wants to run right most of the time. I'm goingt o double check the points in the new distributor now, though I have no idea why that would cause the intermittent-ness that I'm seeing. Then, maybe, it's just time to replace ALL the vac lines...
PS: Where is the idle mixture screw (so I can see if anyone has been messing w/ it) & do you know what the point gap should be?
PPS: Would the idle mix screw being off from the idle speed screw cause an intermittent problem? I would think not, but...