Idle speed oscillates. Not ISV, I think.

[Huw Powell]

try cleaning your throttle body linkages and also the butterflies if
possible.  sounds like it might be sticking open a bit.

"Smeins, Larry" wrote:
> 
> My 87 5kcst has developed the dreaded idle speed fluctuation.  This one is
> different than my previous experiences.  It rapidly oscillates between 1300
> and 1500 RPM at about a two cycle per second rate. Each time the speed
> begins to increase the engine stumbles a bit.  Since the first thing
> suggested for idle speed anomalies is the ISV that is the first place I
> went.  I disconnected the electrical connector from the ISV and no change.
> Even so I removed the ISV and cleaned it, again no change.  I then went
> looking for vacuum leaks.  When I remove the dip stick the oscillation
> frequency decreases a bit.  When I take a propane torch, spewing propane,
> around all available vacuum lines and ports I get no change except for when
> the propane is sprayed into the air filter snout, which increases the rate.
> This problem has been going on for about 5 days and twice the idle has stuck
> in a high state, 2200 RPM, but I have not been able to purposely induce this
> condition.  Another thing that is happening is when I am running at speed
> and remove my foot from the accelerator there is a delay of 1 to 2 seconds
> before deceleration starts and then it is very abrupt.  It is not a smooth
> transition like before the idle anomaly started.
> 
> All help appreciated.
> 
> Larry from Loveland, CO

-- 
Huw Powell

http://www.humanspeakers.com/audi/

http://www.humanthoughts.org/