I had to go out and get a new timing light. naturally the pep boys only had the hundred dollar one. it has a tach built into it and a couple buttons to read the timing at different degrees of advance. No instrux came with this thing. anyone ever used one? I just set the thing at zero degrees and went from there. It's neat, but what use does the adjustments have? I am used to the old kind with no adjustments that you just hook up and go.