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