Actually it stopped being called the Twilight Shoreliner before it lost the sleeper. It went to the old name for that run, The Federal. Maybe a year or so after that name change is when the sleeper came off.
Actually, it depends on which time it lost its sleeper.
It ran as the Twilight Shoreliner with a sleeper until April 2002. At that time, Amtrak seemed to think they had extra Viewliners laying around, and even placed one on the Kentucky Cardinal for a very brief period (which was to be hooked up to a transition sleeper on the regular Cardinal). That setup lasted barely a few days or so when the Auto Train derailed, and they started robbing Superliners throughout the system. A week or so later (give or take), they converted the Cardinal to single-level, and I think that's when 66/67 lost their sleeper the first time.
Shortly after that, David Gunn took over, and (perhaps by coincidence, perhaps by his order, I won't pretend to speculate on that one) within a month, the Viewliner from the Kentucky Cardinal was moved back to 66/67 (still the Twilight Shoreliner).
My memory becomes a bit hazy after that, but it's possible that 66/67 may have briefly lost their sleeper again, while still running as the Twilight Shoreliner.
Then, in either spring 2003 or spring 2004 (I forget which), the train was relaunched as the Federal (operating only to DC, not to VA), and sleeper service was restored (or maybe it continued). After that, a couple of harsh winters did a number on the Viewliner fleet, and 66/67 lost their sleeper, along with the Boston section of the Lake Shore Limited. Some time after discontinuing the sleeper, Amtrak re-extended the route to VA and dropped the Federal name. This may have been around the time when Acela Regional became simply "Regional."
If I feel like it, I'll try and dig out my old timetables, as well as read some old NARP postings (plus other records I have) and try and track down more specific dates on when this all happened.
