I'll take a crack at this...
According to page 176 of the
CNC Programming Handbook, the dwell command might not be accepted during the G73 canned cycle. If your machine does not pause, that just may be because it won't pause in that canned cycle.
The book suggests that only the G76, G82, G88, and G89 cycles accept dwell, but then it confusingly offers that technically all canned cycles accept it...
Try the Dwell command, e.g. "G04 P500" to see if it will pause at all, and maybe read the manual for your machine to see if P is allowed in the G73 cycle.
I think I would also try rearranging the line and put the P address before the Q and F addresses to see if that helps.
By the way, the units for P are milliseconds, so 500 would be a dwell of one half second.
Good luck,
- Just Gary