K-Jet /PIC hybrid

[Bernd Felsche]

Orin tapped away at the keyboard with:

> > pat ford tapped away at the keyboard with:
> > 
> > > are they cis based?? maybe a different dampening system or the
> > > palte working against a spring instead of gravity....  I took a
> > 
> > Definitely K- and KE-Jetronic. From about 1980 to 1991.
> > 
> > Don't know about what sort of springs, etc. The problem is one of
> > inertia - specifically that of the plate and the lever. Putting a
> > stiffer spring in the system would probably only exascerbate the
> > massive turbo-lag.

> There are no springs.  The plate is pushed 'down' by fuel pressure
> and up by air flow.

> My guess would be that the plate would be as high as it goes most of
> the time at the Audi Q power levels and fuel would be controlled
> by the pressure difference across the metering slit, not the size
> of the slit - ie by the 'lambda' frequency valve (which incidently
> is used in the UK quattros which _don't_ feature an O2 sensor).

> Note that K-lambda was used in Audi 5-cyl turbo engines up to
> 1991 models at least (Canada and non-quattro US that I know of).

You're mostly correct, but not entirely. The WR and GV (147kW)
engines produced from 1980 to 1987 didn't have the "frequency" valve
at all.  The MB successor to those engines had an external fuel
pressure regulator and damper bolted on the side (where you'd expect
a frequency valve) with what looks like manifold-pressure sensing.
Still no fuel injection electronics!

AFAIK, there are only two AQ's within about 3000km of here, so I
can't check very easily.

-- 
Bernd Felsche - Innovative Reckoning, Perth, Western Australia
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