ISV? Engine spinning down slowly (was 20v Stalling)

[Dan Sinclair]

Thanks for the input John - I appreciate it.

To address the slow engine spin down?  No, I haven't cleaned the ISV.  I
took it off and took a look at it.  Looked pretty clean.  I recall some
division on whether these were safe to clean with a shot of carb cleaner
etc.  I have the Hitachi unit if it matters.

I also took off the intake boot, hoses, etc. and blew through them all.  No
obstructions.  But when I blew into the crankcase breather pipe (metal,
plugs into the bottom of the intake boot) it resisted being blown into.  It
reacted as if I were inflating something, then air rushed back at me when I
stopped.  Is there a back-pressure diaphragm/check valve in there or
something?

The slow spin down of the engine is a bit worrisome.  It again seems to
happen about every 5 - 10 releases of the throttle, and if I'm decelerating
to a stop, the engine keeps pulling me along rather than decelerating.  It
behaves like a weak cruise control vacuum - trying to hold the engine RPM
rather than letting it drop normally.  A little unnerving in traffic...

-Dan
1990 CQ

-----Original Message-----
From: John Graham [mailto:jgraham1 at erols.com]
Sent: Monday, May 06, 2002 5:39 PM
To: Dan Sinclair
Subject: Re: Update on 20v Stalling


On 5/6/02 11:35 AM, "Dan Sinclair" <dsinclair at icare.snalf.com> wrote:

> Thanks Darin for responding.
>
> To recap - Saturday my '90 CQ was stalling at every stop.  Wouldn't idle
at
> all for a time - just died if you didn't hold the accelerator.  Running
> rough.  Completely carbon fouled a near new set of Bosch Silber plugs.
And
> the engine was spinning down very slowly - from 4000 RPM to idle took
> several seconds - slowly drifting down the RPM range.
>
> Return trip home (about 250 miles of highway driving) the CQ is now
running
> close to normal.  No stalling.  Idles a bit fast - about 1000 RPM - but
very
> close to normal.   The engine still spins down very slowly every 5th -
10th
> deceleration.  But more often than not it's spinning down normally.
>
> What gives?  Could all of this really be bad gas?
>
> I searched for vacuum leaks, etc. and found nothing amiss.  I did see that
> there seems to be dissention in the Audifans Archives as to whether an NG
> 20v will stall when the oil fill cap is removed, or the dipstick is
pulled.
> In the archives, several 20v owners confirmed that there cars run
perfectly
> without the oil cap or dipstick.  Mine does too.  Neither affects my idle.
>
> Anyone have suggestions on the slow spin-down?
>
> Thanks,
>
> Dan
> 1990 CQ
>
>
>
>
>
>
Have you cleaned out the idl control valve?

John Graham
1990 CQ