88 5kcstq poor running - update

[Livolsi, Stephane]

Last nite I did a bunch of stuff and still the poor running.  This
morning I noticed that under a part throttle application, trying to
accelerate, I could tell that I wasn't getting the power I should be and
that it was running rough, and boost gauge was at .8, then without
changing throttle position, it cleared up for a second, power surged and
boost jumped to 1.1, then power dropped again and boost dropped to .8 -
does this mean anything to anyone? anyone? Mr. Bueller?
 
here's what I did. Checked all vac hoses for leaks - all good
Michelin man removed, compressed and holds. visual inspection shows it
is in good shape, no cracks.
checked the cold side of turbo and it turns freely with very very very
little play in the shaft.
checked the crankcase breather and the tee, wastegate hoses looked good
(but did not remove them) and ISV hoses are good.
replaced fuel and air filter (air filter was really dirty and I know why
- very difficult to do with the Euro lights)
replaced the radiator - this was incidental as I broke the neck off
while leaning on it.  My bad.  Fortunately I had the relatively new one
out of the parts car.
 
What else is there, man?
 
DPR? - if someone could take a few minutes and explain how this works
and how to test I'd really appreciate it.
potentiometer? - I don't quite understand what this does, but I do
understand how pots work in general - could there be dead spots on the
pot that buggers up the mix at certain throttle positions but not
others? 
 
This weekend I will be doing the following:
 
removing exhaust and checking the cat
swapping the coil for the known good one from the parts car
checking the idle/wot switch over really well - I don't think I can swap
them as it looks different on the 2 cars
 
 
If all else fails, swap the whole fuel dist from the parts car.  After
that I can't think of anything else other than swapping the whole engine
from the 86 into the 88.
 
Stephane