'89 200q power problems

[Ben Swann]

Could it be the timing belt is off a tooth or more?  I'd speculate that if
it were too advanced then you are suffering from low RPM performance.  When
you reach higher RPMs coupled with the boost, you have all power in upper
RPM range where the torque/HP is skewed.

I don't know if that explains the sputtering and smoke though.  That may be
Oxy. sensor.  Also the mutli-funtion thermo senders don't seem to last to
long - that would cause problems like this too.

[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 turbo charged 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]