Date:         Thu, 10 Jan 2002 08:54:03 -0800
Reply-To:     Don & Christina Preston <betsy@UTAH-INTER.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Don & Christina Preston <betsy@UTAH-INTER.NET>
Subject:      Re: Idle stabilizer

Late to the discussion, I know, but this is the one main problem I have with
my van.

I've been running with my ISV disconnected for a few months because I could
never get the idle to sit at 900rpm. With it disconnected, I have to rest my
foot on the gas pedal for a minute of two on cold starts.

Now, with the ISV connected, my van will idle up to 3000rpm! If I pinch the
tube going from the ISV to the AFM, then the idle returns to normal.

My van used to have power steering and A/C, but I have removed both. I'm
wondering if maybe there is a fuse or relay somewhere in the van that used
to control the PS or A/C that is causing this? I've noticed that having the
IVS disconnected causes the van to run a good bit richer, which can't be
good for a number of reasons ;-)

What I've replaced:
Idle Stabilizer Valve (on top of the motor)
All vacuum lines in the engine compartment
Temp II sensor
Ground Straps (also added another to the right head)
O2 Sensor
Throttle Positioning Switch (bottom of the AFM
Hall Sender Unit (in distributor)

I pulled the Idle Stabilizer (switch? controller?) behind the rear-right
tail light, and it looks good. But I may replace it anyway.

Any other ideas? Maybe we can figure this out before we all end up going
broke replacing parts :-)

Thanks!

Don Preston
Seattle, WA
 '87 Wolfy GL (ASI conv. in progress...)
~Betsy the Mp3 Bus~

> At 12:02 AM 1/10/2002, Blake Thornton wrote:
> > > however, cold starts are a pain, because the Idle Stabilizer Valve
> > (ISV) keeps
> >
> >I haven't noticed cold start problems with the idle stabilizer
> >disconnected yet (and its been cold).
> >
> >And, that makes me wonder about your terminology.  When you say valve, I
> >think of a mechanical valve opening and closing - like the auxilary air
> >valve -- it opens and closes to let more or less air in the engine.  But,
> >when I say idle stabilizer, I'm thinking of the little green box on the
> >left side of my van with two funny shaped plugs that I can connect
> >together.
>
> The 2.1l engines have a solenoid-operated idle-stabilizer valve with an
> associated control board -- it bleeds air past the throttle plate.
>
> The 1.9l engines have a completely electronic circuit that adjusts timing
> on-the-fly at low rpm -- with a properly operating idle stabilizer you
> should see the timing bouncing all around at idle, which is why you have
to
> disconnect it to set the timing.  If your engine runs better without it
> than with it, strongly suspect it's bad.
>
> Re your other post, it has no idea whether the throttle switch is closed
or
> not, it's connected between the Hall generator at the distributor and the
> ignition module on the firewall.  All it sees is rpm.
>
>
> > > the engine idling at 1000 rpm when cold. The operation of the valve is
> > related
> > > to the signal from the Temp II sensor to the ECU. Cold, the ECU
circuit
> >
> >So bypassing idle stabilizer cuts off the signal from the TempII sensor
as
> >well?  Interesting, and that would explain the difficult cold starts.
>
> That's strictly related to the 2.1l system.
>
> david
>