200t: lousy drivability, boosting and whistling

["Gerard van Vught" <gerard@acenet.co.za>]

Hi!

Me again with my 2nd-rate 1990 Audi 200t. Just had the big-end
bearings done.

Am going through the system and replacing vacuum and pressure lines.
Still need to check "Michellin Man" IC to IM hose, but I suspect it
is bust anyway by oil bits on underneath of the hose. Dealer cost
is $110! Anyone know a cheaper and better replacement or what type
of companies to bug for such a hose?

Problems going on right now are as follows. The electronic boost
gauge is slow, I know, but it feels like it is reading properly
according to the seat-of-pants gauge. Max boost reading I get is
1.1 bar (very hard push to get it), on average the gauge reads
0.9 bar pushing the throttle to 2/3 open. I will be pulling the
manifold-WGFV hose today or tomorrow and plumbing it directly into
the WG in order to determine for once and for all whether my FV is
bust. (That is, if the boost builds properly this time then the FV
is stuck open and only gets vacuum from turbo intake, ie. reduced
boost!)

Next, I took the DMM to the pins of the WOT switch today. Reading
came back as +/- 8 ohms resistance with idle switch closed. 0 ohm
for it open. Put the thing across the WOT pins and got back 0 ohms
closed and 0 ohms when the thing was way over the 2/3 throttle point.
Could this mean the WOT switch has lost the internal contact for the
WOT position? What care must I take when removing the switch to
resolder the points? Any danger of springs popping in all directions
when removing the switch from its mount point? Also, WOT switch is
$72, too much for me.

Big-end bearings were replaced, hard "clacking" at about 1600RPM is
gone completely. Only "clicks" left come from the lifters. They're not
loud, but how loud must loud be in order to trip the knock sensor
and fool the computer into thinking knocking is occuring?

Full symptoms: drive up to 80km/h and at that point whistling starts
coming from the motor (could be the IC-IM hose), this whistling can
get loud (could it be turbo bearings?); boost sucks (!!) and slow
internal guage (that was reporting overboost conditions about 3 weeks
ago) never sees more than 1.1 bar, car feels like it never sees 1.1
bar, I can push the throttle almost to the floor and it'll still feel
like I'm idling, I pushed it hard this afternoon and when it shifted
from 2nd to 3rd (auto tranny) it felt like the car was about to give
in and die, only got up to 120km/h (very slow accelleration beyond
the 80 km/h mark); when the whistling is going I can back off the
throttle and the whistling will die away slowly (can this be a cracked
EM?); when gunning it hard the car will "flutter" when boost starts
showing (ie. doesn't seem to get ECU assistance), redline is never
reached at all!

My opinions:

        1. probably a bust WOT connection point in the WOT switch.
           Shouldn't the results be that the WGFV will never be
           operated as it only gets signals when WOT is triggered?
           Also, no extra fuel feed, right?

        2. Perhaps something with the IC. How difficult to pull the
           IC as a Saturday morning job and check for blockages?
Ð0A
        3. cracked manifold causing the whistling.

        4. faulty fuel distributor and air meter, but don't the
           equipment to check it all.

        5. rubbish fuel. Should I try to get an octane additive? The
           only fuel available here is 93 leaded and 91 unleaded.

        5. gearbox...nuff sed. Lately shifts have been more noticable,
           and sometimes the car will want to die during a up shift
           while trying to push hard.

Other info:

        1. I replaced the PCV t-piece (valve housing) and the pipe
           from the airbox to the VH last week. Both were completely
           eaten away by oil. Should I have done the PCV hose on the
           engine block side as well? What is the average cost for
           that hose?

        2. No idea when the fuel filter was last replaced, but will
           be done next Wednesday at $25 for the filter. The fuel
           pump can be quite loud at idle, a rough sound. Give a small
           bit of gas and there is a short whistle/squeal (a brief
           sound like "voooo") from the engine bay. This mostly
           happens at idle. Any ideas?

Some more questions:

        1. Is it possible to buy new bearings for the K26 turbo?
           Are they available in ceramic form?

        2. The RS2 manifold now being mentioned on the list, how much
           is it? If my manifold is cracked (checking next week) then
           I might as well plan a good replacement for the future?
           How much better does it work than stock EM? Is it for the
           turbo MC engines?

        3. vacuum hoses: could anyone explicitly list all the vacuum
           lines on the turbo side of the MC engine as I'm sure there
           are some that I don't know of? What else could cause
           whistling sounds? Alternator? Airbox? Fuel distributor?

Sorry for the long message. Thanks to anyone with suggestions.

G.