RP, yes rotor phasing, where the rotor (point/tip) is in relation to the cap when it fires, what you see when the light "freezes" it. Yeah that is what the MSD tech said. I know that the rotor (tip) does not change as the mech advance comes in. I've seen it at least 6 times with my dist work & I went out yesterday & rechecked again cuz I had understood that all (3) of us were going to do that so I held up my end of the deal