On my recently acquired '85, the engine temp. gauge seems to take a good
15-20 minutes to warm up.  I haven't used the vehicle much altogether, so
my data are limited, but I'm wondering if there are any thoughts out there
on what might cause this.

My first guess would be the lack of a thermostat (or one stuck open - does
this happen?).  I haven't checked this yet due to the more difficult
location of the thermostat compared to the '87, and I'd be interested
in hearing about any other possible culprits.  The gauge stays in the
middle once the engine has been
run a while, and when idling the low speed fan comes on a little sooner
than I'm used to in my '87.  This is a subtle difference though.  I only
thought to question the gauge because, for some reason, the gas gauge
doesn't indicate full even when the tank is full.  Instead, it indicates
just over 3/4 full.  I'm not too concerned about this as I tend to use the
trip odometer, but any thoughts about this would be appreciated as well.
I have no reason to believe that the two gauges are related.  Rather, as
has often been discussed on the list, a problem displayed by the gauge may
be a problem in the gauge/sensor rather than in the device which it is
gauging.

Thanks for the help,
David