Power loss, questionable mechanics.. WTF?

[ian@bluemoon.hplx.net (ian Butler)]

Usually I don't post asking what the heck is wrong with my car.  But since
it's been at a mechanic for a week and a half, it seems a good option, since
it has both them and myself stumped.

For a long time (most of 2002) my '88 Scirocco 16v has had an odd jingling
noise (like keys jingling in a pocket) around certain RPMs.  It gradually
started losing power, and pinging at speed with a load (like trying to
accelerate up a hill on the freeway.)

A month or two after that, the muffler failed, and I took the opportunity to
replace it with a Techtonics system (cat-back), the expensive sort with a
Borla muffler.  It didn't help my pinging problem, and performance continued
to suck.  That was my first $500 in the hole.

I took the car into a VW dealer for a tuneup, "major service" they called
it, for $400.  No obvious effect, so I went about replacing service parts on
my own that they seemed to have failed to do.  This included air filter
(K&N), fuel filter, oil change (Mobil 1), plugs/wires/rotor/cap, and
ignition module (my stupidity -- it was the Hall sender grounding after I'd
knocked the zippy-tie off its harness, probably there from the when the PO
replaced the cap.) No obvious effect, other than being out $500
more.

A couple weeks ago the car wouldn't start at all.  I had it towed to an
independent mechanic, and they replaced the starter (not necessary, but it
was on its way out) and cleaned/flushed the fuel system.  There was low
pressure at the fuel distributor, and an injector was stuck open and
flooding the engine.  I wasn't sure I bought the stuck injector bit, but the
guy does know CIS systems.  They also checked compression (135/135/135/50),
ignition and valve timing, exhaust emissions, all within spec except
cylinder #4.

So!  I got it back Friday, $505 later, and drove it halfway home before
returning -- the car wouldn't go faster than 45mph, and required about 3/4
throttle and judicious clutching to get it to go at all from a standstill.
Not exactly a solution to my previous low power condition, which was
70-80mph top speed!

Any ideas what in the world is wrong with this car?  And, can anyone
recommend a good metro Detroit-area wrench?

Thanks in advance,
ian Butler / ian@hplx.net
'88 Scirocco 16v, '87 Syncro GL