Well, I remember now why I let my van sit for so long...

Now that I've gotten the van to start up again after several years
(thanks again to the List!), I'm having some other issues that I'd
thought I'd check about with the List before I jump into it on my own.
Of course, I'll be checking the  archive as well on this-

My idiot TEMP light is on constantly from the moment I start up. As
the van idles, temperature goes up slowly about midway on the gauge,
then the radiator fan kicks in (loud). There looks as though there are
lots of bubbles coming into the reservior in the back, so I'm sure it
needs to be bled at least.

After idling for about 15-20 minutes my oil pressure slowly creeps
down on my gauge.
When first starting, pressure is around 40 and then as it heats up the
pressure falls until the idiot light and buzzer comes on. (I have a
VDO oil pressure gauge hooked up)

The engine is idling ok, although it's far from smooth and
perfect...Of course, when both of these indicators light up, the
engine dies pretty quickly, or I turn off the ignition.

Any thoughts on where I should start to look to fix this? This engine
has a total rebuild, my first, so I am fearful that I did something
wrong along the way (ie... bearings) I changed the oil pump but did
not change the plate in front of it. I know I've seen something about
changing it when you replace the pump. Think this could be the cause
of the pressure drop? It's got a new VW filter, relief valve, 20-50w
oil. What could be wrong? What tests should I be doing?

My plan so far for tomorrow is to bleed the system first and see if
the oil pressure problems are being caused by the oil getting too hot
and thin. Also, I'm going to check the blue temp sensor (this is new,
but has been sitting for awhile)  Sound good? What next?

THANKS!