80Q Reving on its own

[David Miller]

    My '90 80Q just started acting very oddly, and in a most distressing
way.  It seems, at random times, whether I'm in gear or not, the engine will
not actually go below about 1500 rpm.  It seems to blip the throttle on its
own and the rpms will jump up to around 1700 before falling back down and
the process starting again.  My idle, when I can get it to idle, has also
been affected.  It will at times idle fine, but other times does the same
searching bit, but this time between 700-900 rpm.  In addition, it will
sometimes rev freely for a moment the minute I take it out of gear.  When
I'm in gear and the 1st problem happens, I have a small problem with
unintended acceleration, but I'm quick to clutch in to avoid it.  I really
don't know what's going on here, perhaps a vacuum line is no longer sealed?
I checked to make sure the throttle cable was still freely moving and it is.
Any help anyone could give me would be great.

Thanks,
David Miller