Are you using the "save" function of the tracklog? Saved tracks in Garmin-speak do not store time information
(unfortunately, but that is their design). You don't need to save it in order to download it (or keep it on the
unit indefinitely). Only track points in the active log will have time/speed information.
I am not sure about elevations. Some older Garmin units did not save elevations with the tracklogs at all.