I just downloaded the 1000+ page Bentley shop manual so i will look it up, thanks. This is an involved process so it will have to be done when I have more time, perhaps tomorrow. The idle is roughly 1900 and doesn't move more than 5-600rpm when warm so I will try and see what happens.
 
Thanks
Mike
 
-----Original Message-----
From: "David Beierl" <dbeierl@attglobal.net>
Sent: Sunday, May 4, 2014 14:16
To: mike@BOSSSOLAR.COM
Cc: vanagon@GERRY.VANAGON.COM
Subject: Re: Are all 2.1 engines digifant?

At 01:51 PM 5/4/2014, Mike Holm Toronto wrote:
>Cool. I'm still working out the possible reasons for my idle sitting 
>at 2000rpm. I cleaned the Idle valve (which has been unplugged and 
>taped up by previous owner) to no avail. Another one is being posted 
>as we speak but if the problem is in the module, it would be good to 
>know and figure out how to fix it. The modules are a bit costly so i 
>hope it is not that.

--> The idle valve can only raise the idle, never lower it.

You have to set the base idle down to the specified idle speed using 
the big plug in the side of the throttle body.  Engine should be 
fully up to temp including oil; electrical consumers and radiator fan 
not running, vapor canister purge line pinched off, oil breather hose 
removed and plugged, idle valve unplugged,  oxygen sensor 
disconnected with ignition off to reset the ECU memory.  The complete 
setup and procedure begins on Bentley 24.50.  If you haven't got 
Bentley let me know and I'll photograph the pages for you.

If the throttle body is worn (and of course if there are vacuum 
leaks) you may not be able to set the idle down to spec using the 
plug.  The right answer is to replace the throttle body, but you can 
get a bit more range out of the plug by soft-soldering a shim onto 
the end of it.

If the throttle cable (or rod on auto-trans) is too tight the 
throttle plate may not be reaching the idle stop.

If the throttle switch isn't closing at idle the idle will never 
settle down below 1,000 rpm the way it's supposed to; but it will 
only be slightly above 1,000 and a bit wavery**, not up by 2,000.

**on my '89 with any of several different ECUs but the same idle 
control module, anyway.

Yrs,
David