velere54 wrote:
The timing must have been ok after the work I did. What could cause it to jump?
I'll only attempt to answer the part that I have dealt with. But low pressure is one thing that would make the timing jump. If your engine does not have adequate oil pressure (and thus the tensioner is not pressurized/ extended out) when you crank the engine for the first time, there is a possibility for the chain to jump the teeth before the tensioner catches up and tightens the chain.
...all depending on how devoid of oil the tensioner was. The spring in there does a decent job of pushing it out, but it could happen.
Hopefully your issue is much simpler.