ISV not closing completely?

[Huw Powell]

> I cleaned the ISV and it seems that when in a closed position, it still has a small
> opening,
> maybe 2-3 mm wide.  Is this normal or should I get a new valve?
> The car idles a bit high, just under 1000 rpm.

it's normal.  note that it has three pins - one is ground, and power to
one opens it and power to the other closes it.  when operating, this all
happens very fast, the amount of time open ("duty cycle") is what
regulates the air flow, not "how far" it opens.

I wouldn't worry about an idle under 1k rpms, so long as it is
consistent.  My 89 90Q sometimes rests at 1100 or 1200 for a bit, before
dropping to 800-900 or so.  I think there are a number of factors
(besides the obvious A/C) that affect exactly what idle speed is
"chosen" by the ECU.

--
Huw Powell

http://www.humanspeakers.com/

http://www.humanthoughts.org/