[xj] Diagnosis Opinions

Hi gang, I have a slight problem that maybe someone can chime in
on. My '85 SIII runs great except when starting from cold, it will
start fine and run fine, but will take an occasional nose-dive in
PRPMs down to 200 or so then bounce back up to ~750-800 (which is a
bit disconcerting). I suspect the AAV. I looking into it and it
appeared to be closed when cold but I’m not sure it was cold enough
to verify. Also, I don’t believe the idle speed is different when
starting from cold. Does this symptom sound familiar to anyone ?
I ordered a couple of right angle torx wrenches since I can’t get
the thing off with the screw driver type. I don’t think it’s ever
been off before.
TIA–
Jim Legge '85 SIII XJ '96 LR Disco
Washington, DC, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–

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James Legge wrote:

Hi gang, I have a slight problem that maybe someone can chime in
on. My '85 SIII runs great except when starting from cold, it will
start fine and run fine, but will take an occasional nose-dive in
PRPMs down to 200 or so then bounce back up to ~750-800 (which is a
bit disconcerting). I suspect the AAV. I looking into it and it
appeared to be closed when cold but I’m not sure it was cold enough
to verify. Also, I don’t believe the idle speed is different when
starting from cold. Does this symptom sound familiar to anyone ?

It does, Jim - at least the ‘no high idle’ bit…and starting from
cold…:slight_smile:

The AAV should be about half open virtually irrespective of ambient
temps - as long as the engine is ‘cold’. You can try and prise open an
eventually ‘closed cold’ with a thin screwdriver - as a test only…

You don’t need to remove the AAV for this ‘test’ - it’s only to check if
the engine is more willing with a (half) open slide. You may get away
with some slide exercise, but if the AAV refuses to operate some more
work is needed. With the slide permanently open you may get some hot
start difficulties…

The ‘nosediving’ cold rpms may be related to this AAV problem - engines
don’t like low idle when cold. Bu do verify the AAV first…:slight_smile:

Frank
xj6 85 Sov Europe (UK/NZ)===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/index.html
Archives: http://www.jag-lovers.org/lists/search.html

To remove yourself from this list, go to http://www.jag-lovers.org/cgi-bin/majordomo.

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