she starts, she won't run - 1990 200QA Update 3

[David Michael]

I spent more time working on the ailing 200QA today, and it is not looking
good. The biggest problem now is that it is blowing great billowing clouds
of smoke or steam out the tailpipe. Which it did NOT do before I brought it
to the mechanic. Initially the cloud is blue tinged, but after a few
seconds, its mostly white. But it has essentially NO smell.I checked the
compression on all the cylinders 165, 165, 162, 161 and 140. The 140 is a
little worrisome. A little oil in the cylinder brought up the 170. So it
would seem the rings are a little worn, but for a car with 120k, even 140 is
not horrible?

It terms of getting the car to run, it will start and idle, but won't
accelerate (never mind the embarrassment of the cloud I generate when I try
to drive it). I checked the control pressure when cold. It measured 20 psi
at 30F degrees. That seems high, which would make the car run lean. It
should be closer to 10 I think, at least by extrapolating the curves in the
ALLDATA CD. Anyone know for sure? The Bentley has values only down to 68F.
The system pressure is correct. After the car had idled and warmed up, the
OX sensor freq. valve was going to 85-90% (full lean), and then back down to
45-50%. This is with everything hooked up, (not  unplugged and
disconnected per the Bentley for setting the mixture). But I do not think
its supposed to swing wildly like that.

I am not convinced that the smoke/steam clod and poor running are directly
related. Not convinced that they are not either.

Any suggestions on what to do next?

Dave
90 200QA 220K
07 EX-L 4WD 0.003K (sad, but true)