Re: High boost problems on '91 200QW (3B)-advice?

["Dave Aukerman" <mhauk@ccsdana.net>]

More than likely a bad plug wire.  If its arcing, under-load power will
suffer and bucking will occcur.

Dave

----------
> From: James A. Desveaux <desveaux@ucla.edu>
> To: quattro@audifans.com
> Subject: RE: High boost problems on '91 200QW (3B)-advice?
> Date: Wednesday, May 19, 1999 3:14 PM
> 
> 
> Over the past few days, I've encountered some boost problems.  I first
> noticed this on a steep grade in the Oakland hills last week.  I had the
car
> in 3rd gear, above 2000rpm, and the car began to buck a bit. 
Downshifting
> to 2nd helped.  Previous to this incident, the car would've pulled
through
> the rpms just fine, especially since I changed the turbo bypass valve
last
> fall.  On the way back to LA last night, I wanted to make sure there was
a
> problem.  On the Ventura grade, I slowed to about 55mph in 5th, and then
> attempted to accelerate rapidly up the grade.  THe boost gauge went up to
> 1.7 bar, and then 1.8 bar for an instant, but with difficulty.  THe car
> again started to buck, and I backed off, and downshifted.  I've done with
> grade, and the gauge has gone to 1.8 bar easily, and on a couple of
> occasions, 1.9bar.  It has a mild IA chip that the previous owner had
> installed a few years ago.  
> 
> THe engine just turned 100k last week.  As I said, it has an IA chip, and
> the usual maintenance items.  I changed the plugs last fall and put in
> F5DPROs, as per spec.  I also replaced the high tension wire between coil
> and distributor.  I also replaced the multifunction sender for the temp
> gauge and other things.  Today I checked the lower high pressure boost
hose,
> and the upper one.  Both appear to be in very good condition, with no
cracks
> or holes.  Other than this boost problem, the car runs great.  It idles
> smoothly, and doesn't stall and run roughly, except when under high
boost.
> The problems seem to begin when it reaches about 1.6bar.  I checked the
> codes, and I'm not sure they tell much.  Now I get three codes 2111,
1111,
> and 2234.  Tthe car starts easily, and doesn't exhibit any of the
symptoms
> described in the BEntley for 2111 or 1111.
> 
> It has a K&N filter, and I confess that I haven't even looked at it since
I
> bought the car 12k ago.  Other than that, I've been pretty meticulous
about
> upkeep.
> 
> Any ideas?  Similar experiences?  TIA.
> 
> - Jim