I finally set up my vacuum advance and it seemed to be working great. Manifold vacuum providing 7* additional advance at idle for a total at idle of 25* . So problem#1. While setting this up I notice what appeared to be an intermittent jumping of the advance from idle up to full advance (34* in by 1500 rpms). Hard to tell if its the advance or an intermittent spark causing it to look like a jump in the timing but I think its the advance. Problem # 2 I shut it off and when I re-started it the timing at idle was reading off the chart advanced and no matter where I turned the dial on the timing light it only changed it by a few degrees. I started to increase rpms and it dropped down to where it should be at around 1100 - 1200 rpms then climbed normally to 34* at 1500. I disconnnected the vacuum advance and tried it again with the same results. I have a Dave Ray converted stock dist with gm module only a lttle over a year old that has worked flawlessly to this point. What could make it do this so suddenly? Any thoughts on these two issues?
