FW: Help- Idle is driving me NUTS!

[Reid Bishop]

<I apologise if this is a repeat- I swear the two times I sent this message
out before, it never made it to the list...>

I'm about to tear my hair out.  I simply cannot get my 4.3 to idle properly
(to my satisfaction) after several tuning attempts.  Tried on both a 7747
and 8062 ECU.  Here's the skinny:

BLM's are always running 101-109 at idle, no matter what I do with the VE
tables.  Fuel pressure is fine- right in spec.  Every time I reduce fuel in
the VE tables around my rpm/map idle combo, the engine idles WORSE, and the
BLM's don't change.  This last change, my idle is precarious, and it
generally nearly stalls before the ECU rescues it and brings it back for
another attempt.  Within 5 seconds, it nearly stalls again... this goes on
and on.

Other possible hints:  Can't get into closed loop by just idling (even after
10 minutes with coolant at 180) in 40 degree weather, yet once it gets into
closed loop it stays there, even after extended idleing.

My O2 Cross-Counts move very slowly at idle when in closed loop- maybe 1-2
per second at best- yet I see fairly full O2 swings, from 120mv to 850mv.
When in open loop, the O2 cross-counts advance much quicker.

I have EGR basically disabled at idle (Set EGR% to 0 at low map/rpm
settings)

Engine idles GREAT in open-loop.  Just gets crappy when the O2 comes alive.

Can't get my IAC's down either (I have no throttle stop adjustment on my
TBI).  IAC generally runs between 33 and 48, with a MAP of 30-40.

What gives?  Is this a sign of a need for a heated O2?  Bad O2?  Is there a
chance an exhaust leak is screwing up the picture?  Am I nuts?

I do have a mild CAM in this engine, along with a Performer intake.  I'm
sure it's affecting things to a degree.  All other VE's have been much
simpler to nail down- and I have the engine running great everywhere but
this darn idle.

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