Audi 5000 idle problems

[Tom Christiansen]

Hi again,

Just reread your email.

>1) The ISV. I know you just cleaned it but the symptoms you describe are
>consistent with an ISV that is allowing engine vacuum to pull air past
>the regulator disk.

Do you mean that the ISV could be worn and thereby allowing more vacuum in
than called for?

>  I think there is an "idle/rpm" cut off which is why
>the rpm drops back down at 1600.

That would make sense.

But there's something I don't understand. Why would engine RPM increase
when more air is pulled into the engine.

BTW: I understand that there are two computer control boxes in the 5000.
Which one controls the ISV? Where do I find it?

Thanks,

         Tom