I posted that my van was running poorly.  Several people (thanks Joel and
Alan) suggested that the van is running richly (and rightly so it seems).
Here is what I found:

Took out my O2 sensor: it was very sooty.  The van ran better with it out
(completely out, it was very loud though).  I might put in a new O2 sensor
eventually, but I put this one back in and disconnected the wire from it.

I plugged in my fuel pressure gauge.  While running, it read a bit above
30psi.  While stopped, fuel pressure dropped about 5-10psi in a matter of
10 minutes (that can't be good).

I changed out my fuel pressure regulator and tried running again.  It ran
better, but here is the wierd part, the fuel pressure quickly flucuated
between 28-40psi.  I mean the needle on the gauge bounced so quickly
between 28 and 40 that it was a blur.  Very wierd.  Anyone ever see this?

I guess the next thing to try is swapping out my temp sensor.  Maybe I'll
give that try right now.  My current temp sensor is only about a year old.

Thanks for any help,
Blake
84 Westy