Ok, thats pretty specific info!

Now I'm looking at something that just shuts the engine down hard, not
a vacuum leak or IAC. Althought the IAC could have acted up that one
cold morning...

I'm going to guess that spark is dropping out. It would be easy to
point to the cam sensor since it set a code, but surprisingly, these
engines can keep running with a lost cam signal (lost while the engine
is already running). I've heard of a cam sensor false code related to
the 3.8 due to a nearby sensor causing something like an RF glitch or a
5 volt sensor supply power glitch but haven't seen it. (Internet
discussion) But I believe what I read was true. And the spinning cam
sensor drive assembly can tighten up or even break, causing noise or
complete cam sensor failure. So all this means is that the code could
be real or a ghost code. Fun......

When you say it died at 3k and 'tried to restart' I read that you lost
full power instantly and before the engine reached 0 rpms it chugged
back to life (as if you were driving along and you turned the key off
for a couple seconds then back on). If that's true it could be any
kind of spark loss or battery power loss to any ignition or fuel
injection component. I think your van would need to be road tested by
a mechanic until it happened. Then possibly road tested again with
test equipment monitoring suspect areas.

Sorry, I'm out of ideas, but if you explain your problem to a good shop
as thoroughly as you did here -- and let them have it 'til it acts up,
you will probably find the shortest path to a correct repair.
Good luck,

Toyota MDT in MO