[urq] I'm SO close to giving up...

[Buchholz, Steven]

John, I think that you've got a good theory ... in fact I'd expect that
it even jives with Dennis' observations ... the only thing to keep in
mind is that on some cars the WOT switch kicks in slightly before the
butterfly is at WFO.  It has been a while since I've listened on the WX,
but ISTR that the switch clicks pretty close to the hard stop ... IST
indicates that the WOT switch should close at about 3/4 throttle, and
when the WOT switch closes the duty cycle goes to somewhere between 70%
& 77% based on RPM.  This would imply that the duty cycle is already
over 80%.  It should be a fairly simply matter to route the wires for
the duty cycle reading into the car and take the car out for a run ... 

Of course this theory would not apply at all with a WR as they don't
even have an OXS Freq Valve ... 

Steve B
San Jose, CA (USA)
> 
> I'm stuck on the idea that the problem occurs at WOT, and that screams
> throttle switch to me.  The WOT switch triggers an open-loop, fixed
duty
> cycle.  All other things being equal, it provides a richer mixture at
full
> throttle.  If, however, the closed-loop duty cycle is already
compensating
> for less than ideal mixture control, etc., etc., you can find yourself
in a
> situation where going to closed-loop at WOT means moving the duty
cycle in
> the wrong direction and going lean.
> 
> I may be full of crap, but it wasn't clear to me that you've
completely
> ruled this out, and I've observed this and messed with it on  my own
car.
> So, I hope maybe this helps!