Re: Idle Stabilization Valve correct operation

[Steve Manning <stephenm@ix.netcom.com>]

I have to admit this one has me stumped.....I have two ISV's in front of
me, one for a NG engine and one for an MC.  I don't have the one from the
3B, which is different (info thanks to Brett Dikeman).  The two I have
aren't opened at all; you can't blow through them.  If you unplug the ISV
the engine will still idle, so air is either bypassing somewhere around the
throttle plate, or.....?

I've looked in every Bentley I have, as well as the Pobst book to try to
get more info on specs for the ISVs, but no joy.  There seem to be lots of
different versions.......SLM

At 01:17 PM 8/15/98 -0400, you wrote:
>While waiting for the oil to drain, I decided to pull my ISv and take a
>gander.  It too, is opened just a crack; maybe a dime's width (not a
>nickel) - can't really get the calipers in there<g> but it is opened.
>De-fibbing with a 9V pops it open smoothly to almost completely open (just
>that dime's worth closed).  Removing power snaps it shut again.  So, it
>seems to be opening/closing the "full amount" with the initial and ending
>positions being "off".  BUT, doesn't there need to be some air going
>through?  I couldn't find any other bypass so I'm confused now.
>
>Also, I scraped the gunk off the mysterious brass insert (set screw?) but
>was unable to turn it also.  Didn't really hork on it though.
>
>What's going on here?
>
>At 10:35 PM 8/13/1998 , Steve Manning wrote:
>>  At 08:59 PM 8/13/98 -0400, you wrote:
>>  >Pulled my ISV, cleaned it w/carb cleaner, lubed w/Liquid Wrench,
>>  >reinstalled; no change in idle; still bounces, and no higher-RPM for A/C
>>  >operation.
>>  >
>>  >The question is, should the valve, when one peeps at it, be open just
ever
>>  >so slightly?  Mine sure is, and it still is.  I'd guess it's open about
>the
>>  >thickness of a nickel.
>>  
>>  Should be closed (should not be able to blow air through it).
>>  
>>  >The second question is, should I do a de-fibrilation on it? :)
>>  >Hey, it says 12v on the side :)
>>  
>>  Actually, yes.  It's a good way to clean it.  But DON'T use 12v from your
>>  car battery, use a 9v battery (like used in a radio).
>>  1.  Spray in carb cleaner
>>  2.  Hook up battery to contacts and click it open and closed.
>>  3.  Repeat until clean.
>>  
>>  Don't forget to check the hoses leading to it for a vacuum
>>  leak...........SLM
>
>
>
>Cheers,
>	Richard
>	88 90Q - <insert pithy witticism here>
>	88 Golf GTi - PRO Rally
>
>
>

Steve Manning:  stephenm@ix.netcom.com
...Physical home: Metro D.C. area, USA
.....Virtual home:  http://www.stationwagon.com