'89 200q power problems

[John David Anderson]

Hi, new to the list again after quite some years, had a few Quantum
syncros and 4000q's years ago and used to follow.  Anyway a few quick
questions I'd love suggestions on.  Picked up an '89 for an appealing
sum and it is a fair car generally but it has a bit of a problem.
Engine is replaced recently (timing belt snapped on PO) with an earlier
5ktq mill with about 95k on it (per reputable place) though compression
falls out at 125, 120, 120, 120, 98 (though car has not been driven so
that may improve if #5 was sitting open.  Problem is that in any gear
from approx 0.4-0.8 bar boost (per the dash gage) at whatever revs
appropriate to give said boost it sort of sputter/gags/misses
miserably.  Not enough that it is anywhere near not driveable, but
fairly cruddy.  The second you hit 0.8 bar it instantly pulls smoothly
and very powerfully through about 1.3 bar until you let off the
throttle/boost whereby it miserably repeats.  It feels more a fuel
delivery miss in the seat of the pants, not ignition.  Once again per
the digital gage at whatever pitiful sampling rate it has there are no
sudden jumps in boost or anything.  While it is so sputtering
apparently it dumps rich smoke out the back per follower.  Two other
perhaps incidental, perhaps not, the cold start is very rough and it
has a hard time running until it gets about 90 seconds under its belt.
The car sat with little gas in the tank all summer and into the
recently cold WV winter run no more than once a month.  The check
engine light is on and I will read the blink codes in the AM.

Anyway, I have years of engineering and engine building VW/Audi
wrenching experience, but I know nothing at all about turbocharged
vehicles other than aircraft and Corvairs.  Any suggestions
appreciated, I'm pretty crafty and will probably have most anything
needed for diagnosis (excepting factory tools 8-)  This obtuse Bentley
set for this car is not helping me any.  I do have a Snap-On CIS
manifold gage test set.

Any help appreciated, please email me direct so as not to waste
bandwidth, thanks.

John
janders1 at mix.wvu.edu