> > There is supposed to be some automatic adjustment based on
> > temperatures, etc, that would be affected by octane,
> > isn't there?
> Nope...no automatic adjustment unless there are knock sensors
> involved - 3.7L/4.7L/5.7L use these (4.7L uses them since late
> 2003 on the "Next Generation 4.7L").
Ahh, right you are. There's a list of things that affect timing,
but not exhaust temperature like i thought.
The PCM adjusts timing for:
engine coolant temperature
engine rpm
intake manifold temperature
manifold absolute pressure
throttle position
So, i wonder if the 180 thermostat prevents pinging directly because
the temperature is lower (which *would* reduce pinging), or if the
lower temperature causes the pcm to behave differently.
I can't think of why it would retard the timing, but it makes sense
(to me) that it might make the fuel mixture a little richer.
eric
-- 1974 Valiant 4-door, 318 1999 Dakota Ext Cab, 2WD
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