A shredded serpentine belt led to my timing jump. A small strand 4" long by 1/8" of serp belt was pulled so tight that it was under my TB covers. Re-timed and problem solved.
Thanks for the info. When you say "re-timed", to reposition the belt you a) removed the tensioner, recompressed the tensioner (or bought new), reinstalled the tensioner, or b) loosened the tensioner without fully removing it, and then retightened it? I'm curious about how much slack you needed.