Well, I don't know what " fuel injection setu on digifants"
means, but I can tell everyone this, and I'm sure most people realize this,
but just in case ...........
If we are talking about an 87 2.1 waterboxer vanagon, idle control for the
Air Idle Valve, aka Idle Stabilizer Valve,  is via small control unit behind
the right taillight. 

This statement is not correct : " the idle air motor is all that's in the
engine bay."
No, there's the box behind the right taillight. 
Funny they hid it there I must say, but it's not that big a deal. 

I can not think of one 'spring tension' adjustment on a 2.1 waterboxer, or
any springs that really affect anything, adjustment wise. 
Spring tension in the air flow meter ?  - not something you would mess with.

This post is confusing and pretty incorrect 'information.'
Scott
www.turbovans.com 

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Mark Keller
Sent: Friday, February 01, 2008 10:34 AM
To: vanagon@GERRY.VANAGON.COM
Subject: ECU high idle

Hi,

I'm experienced with the fuel injection setu on digifants.  I thought
the 87 was such. If so the idle stabilizer is in the ECU, and the idle
air motor is all that's in the engine bay.

As far as useful information, The ECU operates on assumptions, like fuel
pressure.  For a good read, try searching the archives unde my email,
just kelphoto.  Look for how to setup the base fuel injection and you
can see what controls you have, like idle air bypass, spring tension,
and CO mixture.  They are important for cold starts, since no O2 is
available.

The ECU basic start adjustment is based on the above variables to be
set.  From there it adds timining or modifiy fuel pulse, and idle air,
to keep rpm.  If the base values are off, then the ECU adjustments
either over or under correct.  Then the computer gives up on a normal
idle and then goes for a high idle just to keep the engine running.

read through the archives, pmail me, I'm on digest mode, and I can get
you more detailed diagnostic focus.

Mark