[urq] Ideas for rough running continued - Solved!

[Ed Kellock]

I may have had an "AHA!" moment.

I went out the adjust the distributor subsequent to my weekend post
and Ingo's response to see if anything changed with my ignition
cutout.  It didn't.  The car started easily but sure enough the
ignition cutout is still there.

As I sat there opening and closing the throttle, I noticed that the
cutout seemed to occur as soon as I lifted my foot.  Once in a while
it would happen a moment later as the rpms fell.  It did it reliably
enough that I believe I can connect the behavior with the symptom.
Not high rpm's involved, most of the time it was nothing over 2500.

When the ignition cuts out, the tach needle drops every time but the
fuel gauge seems to be unaffected.  And the relay in the fuse panel
that clicks doesn't do it every time, only when the duration of the
cutout is longer.

What's the gizmo that holds the idle up a bit until the car warms, the
idle control?  I think the temp sensor for mine is somewhat defective
because the rad fan had already kicked on once before the idle control
let the idle drop down to a more normal warm idle.  As soon as this
occurred the cutout started happening by itself repeatedly but not
necessarilly enough to kill the engine.  When I opened/closed the
throttle to keep it running I found that I could reproduce the cutout
much more directly always on decel or lift throttle.

Anyway, all of this reminded me of Ingo's sticking fuel plate spring.
Now, maybe I'm pairing apples and oranges a bit here, but the
similarity is interesting at very least.

Is there any relation between the lack of air flow and resulting fuel
cutout as in Ingo's case and the ignition trigger?

Ed

----- Original Message ----- 
From: "Ingo Rautenberg" <irautenberg at comcast.net>
To: "UrqList" <urq at audifans.com>
Sent: Saturday, March 26, 2005 5:02 PM
Subject: Re: [urq] Ideas for rough running continued - Solved!


> It was the Airflow meter.  Now I need to have my exhaust reattached
> (currently held together with baling wire).  Really quite
remarkable.  After
> replacing almost every conceivable possible problematic piece (save
entire
> engine or turbocharger) with known good, I decided to look at the
airflow
> metering plate again, which I initially thought was binding, and
compared it
> with another that I had just recently bought.  What I discovered was
that it
> was not sticking against the venturi wall, but rather that the pin
that
> rests on the leaf spring had actually worn a hole in it!  On decel,
it would
> essentially stick, the pin lodging itself into the hole, choking off
air and
> fuel.  It would not restart unless I turned the CO screw to richen
the
> mixture, which would apparently plop the plate up again.  Some pics:
>
> As seen from below (air filter side):
> http://www.dtwaudi.com/album_pic.php?pic_id=2093
>
> And from above with mtereing plate removed:
> http://www.dtwaudi.com/album_pic.php?pic_id=2094
>
>
> I highly recommend anyone who has similar sysmptons look at theirs
by taking
> off their igloo, removing the air metering  plate (10mm bolt) and
inspecting
> the "rest" area for wear or wear-thru.  Maybe that's your problem,
Ed.
>
> Ingo (tired but glad I finally found the problem)
>
> Happy Easter!
>
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