Re:Underboost: '90 200 TQW IA Stage 1

[mallick@orion.crd.ge.com (John Mallick)]

Tom wrote...

Well, after 15,000 miles of trouble free ownership (ah, except the fuel
pump replacement), the gods have finally bit. 

Max boost, formerly 1.7 or 1.8 bar, is now 1.4. Car seems to run fine up
to that point. I did a visual inspection of the turbo hose and it looks
ok: rubber is in good condition, no visible holes, cannot feel anything
amiss on the underside.

...

Check the clamps on the turbo hose.  Also check all the vacuum hoses
and connections for leaks.  The vacuum hose from the back of the
manifold to the turbo bypass valve runs behind the heat shield next to
the wastegate/turbo and will burn up over time (that was the problem
on mine).  Easy way to check for leaks:  Remove end of air intake hose
from air filter box; bend over and shove hose over mouth; blow into
hose and see if you can build up pressure; if you can build up
pressure, no big leaks; if you can't, go hunting.  

Oh, yeah...don't forget to wash the big black circle off of your face
before your wife sees it :-)  BTDT

John Mallick 
'91 200q (250mi from 100K)