[s-cars] 1.8T coil odd behavior

[calvinlc at earthlink.net]

Dave,

This is extremely interesting.  The reason I say this is because what you
describe is EXACTLY the same behavior I was having on my 2.7T A6 and a
couple of friends were having on their 2.7Ts as well.  In doing some
research on Audiworld I found a few people who had the same behavior and one
gentleman had a good result by getting the ECU re-flashed with a firmware
update at the dealer.  After much consternation and suggestions from the
stealer that I use LOWER OCTANE fuel I finally got them to re-flash my A6
with an update and the problem went away.

The reason I mention this is because my guess is that the coils on the 2.7
are probably not too far from those on the 1.8's.  I wonder if there is
something about the coils needing a longer dwell time or something before
they reach operating temp.  I have no idea what the re-flash from the dealer
changed in my ECU, but my gut tells me that if you can track that down
through some contacts you might be able to figure out what you need to do in
order to fix the problem on your UrS.

I don't think it could be the 02 sensor, since that is not even in the loop
until well after this time period, if I am reading your symptoms right.  I
used to think the problem with my 2.7 was a fuel enrichment problem...but
the coil warm-up idea almost makes more sense because the thermal inertia of
whatever is causing the problem, assuming its related to being cold, has got
to be pretty small to go away within 15/30 seconds.  Good luck!

--Calvin


-----Original Message-----
From: s-car-list-bounces at audifans.com
[mailto:s-car-list-bounces at audifans.com]On Behalf Of djdawson2 at aol.com
Sent: Wednesday, May 31, 2006 7:06 PM
To: s-car-list at audifans.com
Subject: [s-cars] 1.8T coil odd behavior


OK... ever since I installed my 1.8t coil conversion, I have been repeatedly
subjected to a weird behavior immediately following startup... hot or cold.
The car starts fine, and idles fine.  But when you try to feed in the
throttle, it kind of bogs down as if it isn't getting fuel.  It simply won't
take any pedal, and engine speed refuses to increase.  This lasts 15 or so
seconds, and then goes away like nothing is wrong.

This behavior started immediately after my coil conversion, and occurs
almost every time the car is started.

So... I had written off any possible connection between my coil conversion
and this strange behavior until today.  This afternoon, Dennis Graber and I
were working on his S6's A/C... and in passing conversation, Dennis
mentioned this strange behavior on his S6... post 1.8t conversion.  I was
laughing as he described the exact same symptoms I have following startup.
Hence this post.

My questions:
1) Is anyone else that has done a 1.8 coil conversion experiencing this same
behavior?
2) What possible connection could exist between a change of coils, and this
initial startup behavior?

That's it.

Dave
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