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Re: 91 200q owners - low boost


Given the size of the wastegate valve leak you found vs. the size of
the exhaust pipes, I have a hard time believing that is what is
preventing you from seeing max boost (but who am I to doubt Ned).  Are
you sure that the wastegate diaphragm isn't what's leaking?  If you
disconnect the grey hose at the wastegate frequency valve and blow
into it, you should feel it all stopped up (a sealed diaphragm).  If
not, then you may have a leak there.

Hmmm...now that I think about it, is the function of the grey hose and
the wastegate frequency valve to provide backpressure on the diaphragm
to keep the wastegate closed, or is it to provide front pressure to
keep the wastegate open?  Ned's advice about the vice-grips on the
hose imply the latter.  The default position of the wastegate
frequency valve is to provide turbo outlet pressure to the hose; when
energized it doesn't.  Anybody really know?

Keep me informed.  Good luck.  76K on a wastegate is too low for a failure.

John Mallick
'91 200q (99K, and boost still OK)