After checking things out again today (after a lot of rain yesterday)
we found resistances as they should be and continuity in the right places
at the right times but it is injecting WAY too much fuel. Might be the MAP
sensor (anybody got a good one to sell at a reasonable price??) and certainly
not the coolant temp sensor. BUT - we looked at the computer, which we had
put in nice and clean a couple days ago and found that it had a little WATER
in it!! Enough to drip about a teaspoon on the frame member beneath it when
we unhooked it. The inside of the car is DRY. It looks like it is coming in
through the cable!
We have another complete FI wiring harness that Ben has just spent an hour
identifying all the connectors, using the TREMENDOUS manual copy we recently
got that ONLY covers Volvo D-jet systems (all of them) and I think we found
some reasons why certain functions were nonfunctional (thermal timer, cold
start, etc). This harness looks a LOT better than the one that is in there,
although it does have a few cracks in the wire insulation. We note that the
gromment that goes through the firewall seems to form a funnel so if you were
driving really fast on a very wet road, water would splash into the funnel
and probably soak down the cable. To the best of our collective memory it has
not been run in standing water in recent years but we plan to seal between the
gromment and the wires with some kinda sealant on installation.

Your comments are eagerly sought! We do have another computer on the way and
are still searching for a GOOD Manifold Air Pressure Sensor.