Fuel cutoff- what triggers it?

[Doyt W. Echelberger]

At 11:33 PM 10/22/00 -0400, you wrote:
>Hi listers,
>I've encountered a rather interesting problem.
>
>The car in question is an '86 5000CS quattro, MC engine.
>
>My car won't rev past 4400 rpm, at which point the fuel
>cuts off and the car jerks rather violently.
>
>The car feels _much_ more powerful recently, all the way
>up to 4400 rpm.

.................sounds to me like the short thick-walled vacuum hose 
between your WG lower chamber and the intake manifold has blown off or 
sprung a big leak.  Take out the windshield washer bottle and check out 
that line with your fingers, by rolling and pressing its entire length to 
detect hard spots and soft spots. Don't use boost any more until you find 
the cause and fix it.

Doyt


>Boost gauge in the trip computer won't go past 1.2 bar,
>although it would do 1.4 bar previously. Throttle body
>hose is in good condition and less than a year old.
>
>Any ideas?
>
>Thanks,
>Taka