[s-cars] Short term rough idle - follow-up

[Robert Myers]

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Maybe, Vittorio, but I kinda doubt it.  The time interval is so short 
that there is little perceptible temperature change at all in the few 
seconds duration.


At 12:16 PM 1/25/2010, Bares, Vittorio wrote:
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>Seems engine temp related - could it be the sensor?
>
>Vittorio -
>-----Original Message-----
>From: s-car-list-bounces at audifans.com
>[mailto:s-car-list-bounces at audifans.com] On Behalf Of Robert Myers
>Sent: Monday, January 25, 2010 11:28 AM
>To: S-Car-List at Audifans.Com; quattro list
>Subject: [s-cars] Short term rough idle - follow-up
>
>*This message was transferred with a trial version of CommuniGate(r)
>Pro*
>
>Original post:
>
>Hi Y'all,
>
>My well modified '95.5 urS6 has developed a relatively minor but a
>bit disturbing problem.  On initial start-up the engine idles a bit
>roughly.  The idle smoothes out again after a few (perhaps 10-15)
>seconds and becomes as solid as a rock.  Obviously this is not, of
>itself, a major problem but it could be a portent of something more
>serious to come.  Any ideas/suggestions?
>
>Other than the idle problem the car is running superbly.   Let's
>see...  modifications which might be related...  Running the Dave
>Forgie 1.8t coil mod as expressed by Apikol.  All the RS2 mods -
>turbo, ECU, EM, injectors.  Stromung exhaust.  Big FMIC, etc.
>
>Bob
>
>And now the follow-up:
>
>There were several suggestions ranging from "don't worry about it" to
>"try some Techron" to "check out the ISV" to "uh-oh might be a blown
>head gasket".  (Oh joy.  :-()
>
>OK, here's what has been done since the first post:
>
>Item 1 - a can of Techron has been added to a 3/4 full tank of fuel
>and about half of it has been burnt.
>Result 1: idle is smoother.  Not perfect yet but improved.  (It
>wasn't REAL bad to start with so...)  Indicating possible dirty
>injector(s).  I'm planning on doing the Techron bit again the next
>time I fill the tank.
>
>Item 2 - I pulled and inspected all the NKG plugs.
>Result 2 - They all looked the same - dry and with normal coloration,
>no excessive wear.  They looked as good as any plugs of that age in a
>big boost I5.  There is a hint of black deposit on the threaded
>portion of #1 well outside the internals of the engine area.  It is a
>little greasy feeling and left a smudge on the fingers.
>
>Item 3 - The symptoms don't seem to indicate ISV troubles to me so I
>haven't messed with it (yet) - I will if the problem persists.
>Result 3 - none (yet).
>
>Item 4 - While the plugs were out I checked the compression of each
>cylinder (only one try - no repeated testing and averaging, cranking
>time was the same for all cylinders twelve pulses per cylinder) and
>found:
>Result 4 -
>Cylinder        max pressure
>    1              150
>    2              150
>    3              135
>    4              160
>    5              155
>
>Additionally after cranking the gauge was just left alone while still
>connected to the cylinders.  The pressure held and there was no sign
>of leakage - at least not in the short term (a couple of minutes).
>
>I'm not thrilled with #3 pressure but it is pretty close to being
>acceptable.
>
>OK, whadya think?  Should I be making an appointment with my favorite
>independent Audi wrench or should I just quit picking at nits and get a
>life?
>
>Bob
>
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