High idle, problem with idle air motor

[Eric Sanborn]

Last week I sold my 4ktq that I have been driving for going on 8 years
(4.5 years as a turbo).  Over all that time I had no problems with the
idle.  I guess to punish me for selling it it is acting up for the new
owner.  He starts is up and it runs up to about 2200 rpm and won't
come back down.  Other than that it works well.  He is in NJ and I am
in VA so I can't exactly go help him in person, but I want to help him
getting it running right again.

The patient is a 1985 4kq with a 1985 KH turbo engine out of a fwd 5k.
 It runs megasquirt for fuel, but still uses the KH ignition and idle
control.  I had the new owner take the idle motor off the intake
manifold and plug the hole.  It idled properly.  So he swapped in
another motor he had and it started idling very high again even on the
new motor.  He tried spraying them with carb cleaner, same result.  If
you unplug the idle switch on the throttle body it just makes the rpm
go higher.  If you unplug the idle motor nothing changes.

It seams to me that something other than the motor is out of wack
since two different motors give the same result. I have never had a
problem with this system before so I am not that familiar with its
operation.  I have looked over the 4k manual and didn't find anything
that jumped out at me.  I have not found my 5k manual yet (moved last
summer and still trying to find stuff).

 Does anyone have any ideas?

Thanks in advance!!

-- 

Eric Sanborn
http://sofadog.net/projects/