RE: Update to: 1.5 bar cutout on unchipped 5kcstq

["Buchholz, Steven" <Steven.Buchholz@kla-tencor.com>]

	> I also hooked up a test LED to the WGFV terminals, to observe its
	> cycling while driving. The LED showed that the WGFV was being
cycled at
	> WOT until manifold pressure built up to 1.2 or 1.3 bar--which is
normal
	> operation, right? If I stayed on the throttle, though, the
manifold
	> pressure (on the stock gauge) would reach 1.4 or 1.5 bar
sometimes.

	And the LED stops cycling?  It shouldn't.  What's happening is that
the
	ECU is applying all the boost it has to the top of the wastegate and
it
	still isn't enough to control the overboost.

	... on the cars here in the US equipped with the MC-I engine the
WGFV controls boost/vacuum to the top of the wastegate.  If the WGFV applied
boost here it would actually have the effect of _increasing_ the effective
force constant of the WG spring ... if the valve is not energized a slight
vacuum is applied to the top of the WG, which is about all the ECU can do to
reduce the amount of boost applied ... at least in the short term ...

	Usually this is a symptom of a shim or oversize spring in the
wastegate.

	Undo the wastegate top retaining nuts (carefully) and allow the cap
to
	rise under spring pressure.  The gap between the metal part of the
	body (below the diapraghm) and the base of the cap should be exactly
	24mm.  The spring should have a colour dot (blue) and should be 3
1/2
	turns of 3mm wire.
	
	... I have posted my measurements on springs before but I don't
recall my measurements, but yes, the WG spring on the MC-I is much less
stout than the one say on the WX equipped ur-q.  The WG springs I've seen
actually have 2 blue dots.  I would tend to agree that given the fact that
Wallace has already tested to ensure that the diaphragm holds a vacuum that
it is likely to be that the spring constant is a tad too high, the stock WG
cap on the MC-I has a fixed spring perch, so it is likely to be a spring or
a shim ...

	BTW, Wallace, if you want to try another stock spring let me know
... I've got one here you can borrow ...

	Steve Buchholz
	San Jose, CA (USA)