High / fast warm idle 5ktq-- MORE INFO

[Ryan Hoitink]

OK, thanks to those who have replied already, and here's some more info I
got today.  Dashpot checks out OK, cruise control is not interfering, I
start the car with the ISV disconnected, and it starts fine and immediately
rises to 3k rpm, same as with it connected.  Adjustment of idle speed set
screw on throttle body has very little/no effect.  It will cause it to vary
slightly, but only~150-200 rpm.  Upon cold starting, it starts immediately,
then stumbles and dies.  Application of throttle causes immediate death.
Upon re-starting, it is a little slow to start and then stumbles for a
couple of seconds.  Then continuously rises to 3k rpm within 30 secs or so.
Hot starts are perfect, except, of course, for the idle speed.  This is
really starting to bother me now.  Disconnecting the (1-wire) temp sensor
for the ISV circuit causes no change.  I can't find any vacuum leaks.  When
I remove the oil filler cap, the idle drops maybe 200 rpm or so,  but no
more.  Sub zero windchills are not helping me in diagnosing this problem.

Thanks again in advance....

-Ryan


----- Original Message -----
From: "Ryan Hoitink" <rahoitink at students.wisc.edu>
To: <quattro at audifans.com>
Sent: Sunday, March 03, 2002 12:32 PM
Subject: High / fast warm idle 5ktq


> On a recent drive, my car acquired the following problem.  When the car is
> even slightly warm, the idle will rest at a constant 3000 rpm.  When cold,
> the idle seems to be basically normal, but within a minute, it's up
> to 3k.  There seem to be no adverse effects in the output/running of the
> engine, basically it's like someone were holding the accelerator slightly
> down to make the engine run faster.  When I press the accelerator, the
> engine speed rises immediately, no stumbling or dead spot.  When I unplug
> the ISV, there is no change in the idle speed.  The WOT/idle switch is
fine.
> The throttle have full range of movement.(not being held open by anything)
> When I remove the oil filler cap on the valve cover, no change in engine
> speed.  I would normally look for a vacuum leak somewhere, but it puzzles
me
> that the car idles fine when cold.  Any help would be appreciated.  This
> unnecessary "cruise control" is starting to annoy me.
>
> Thanks,
>
> -Ryan
>