All good suggestions, thanks.  The engine in my van isn't sealed off.  The
whole motor gets  covered with dust during prolonged back road travel.
On Dec 21, 2014 6:43 PM, "Dennis Haynes" <d23haynes57@hotmail.com> wrote:

> Why should the idle valve see any substantial amount of dust? That is what
> the air filter is for. If the idle valve is seeing dust I hate to think
> what the engine is ingesting. Same for any oily deposits or good. Oil in
> the intake track is a sign of excessive piston blow-by or a crankcase
> venting problem.
>
> As for the idle going down to 400 rpm don't bother looking at the idle
> valve first. The engine warmed up should never go that low even with the
> valve fully closed. Get the book and get the basic settings correct. If you
> can't use current or duty cycle to set the base idle speed set the idle to
> about 750-800 rpm (engine warm, all consumers off) with the valve unplugged
> or blocked off. This will get you close.
>
> Since it is intermittent you need to look at fuel delivery or mixture
> control. I would take a look at the O2 sensor particularly after changing
> the design (eliminating the heater). Either too rich or too lean can create
> idle problems. Another possibility is a cylinder miss-fire. Again fuel
> delivery-cylinder balance should be checked.
>
> Dennis
>
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
> Of Don Hanson
> Sent: Sunday, December 21, 2014 9:25 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: Isolating an idle problem?
>
> I'll try cleaning the idle control module as per a link posted.  I've
> never cleaned this one and in my installation it sees lots of dust.
> On Dec 21, 2014 12:46 PM, "Stuart MacMillan" <stuartmacm@gmail.com> wrote:
>
> > Best I can do: http://www.gowesty.com/ec_view_details.php?id=23468 <
> > http://www.gowesty.com/ec_view_details.php?id=23468&category_id=&categ
> > ory_parent_id> &category_id=&category_parent_id=  don’t expect to get
> > your core charge back either, but you might get lucky.  I found a used
> > one locally for $75 from Vanagon repair shop.
> >
> >
> >
> > Stuart
> >
> >
> >
> > From: Jim Felder [mailto:jim.felder@gmail.com]
> > Sent: Sunday, December 21, 2014 11:36 AM
> > To: Stuart MacMillan
> > Cc: Vanagon mailing list
> > Subject: Re: Isolating an idle problem?
> >
> >
> >
> > Somebody give me a part number, I'm pretty sure I have a loaner that
> > could be purchased if needed and returned if not.
> >
> >
> >
> > Jim
> >
> >
> >
> > On Sun, Dec 21, 2014 at 1:33 PM, Stuart MacMillan
> > <stuartmacm@gmail.com>
> > wrote:
> >
> > Idle control module, or a vacuum leak (hook up a vacuum gauge).  Try
> > to find an ICM to borrow for testing, they are expensive. It's mounted
> > way behind the right tail light. Not a very good location for a
> > computer that is not waterproofed.
> >
> > Stuart
> >
> >
> > -----Original Message-----
> > From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On
> > Behalf Of Don Hanson
> > Sent: Sunday, December 21, 2014 8:43 AM
> > To: vanagon@GERRY.VANAGON.COM
> > Subject: Isolating an idle problem?
> >
> > I've been seeing an intermittent low idle-sometime no idle with my
> > Digifant
> > 84 van 92 rabbit/fox/Jetta ecu, etc.  This condition is occasional,
> > when not happening, the engine behaves normally, my fuel consumption
> > has not changed.
> >   My normal idle is about 900 rpm.  Recently I have had the idle
> > decide to run at around 400 rpm...it seems to be smooth, but 400 rpm
> > is too low and now the motor sometimes dies down there.  When I cycle
> > the key and re start, it will again run at the low idle...no
> > "reset"... I have a new temp II sensor and new plugs...the old plugs
> > read normal.  My idle control thingy hums as normal and I have no
> > obvious new vacuum leaks. Multiple different fuel sources.  Throttle
> > switch seems to conform to the Bentley, though I have so far only
> > check ed the mechanical, I have not run any electronic diagnosis yet.
> >   Anyone want to suggest the most likely cause to this sometimes dying
> > of my Digifant inline? Tia, Don Hanson
> >
>