My power is gone. Wagon drives like a slug due to fully retarded timming. In other words I have turned the distributor as far clockwise as it will go. If I move the setting in any increments in a clockwise direction it makes that awful pinging sound of the pre-ignition. I am running, but not liking it, 89 octane through the beast. My question is this, "Knowing what is going on so far, is there any other thing that I should check to alow me to advance the timming yet not geting that ping? Timing advamce/retard? anti-knock sensor? Any advice on the timming status of my car would be most appriciated.