Correct - those that you listed do effect timing, but not exhaust temp or
octane (internal detonation).
On the t'stat, you're keeping the engine cooler which does help control
detonation - but also allows for a slightly richer mixture and/or advanced
timing (hotter coolant temp retards timing).
- Bernd
-----Original Message-----
From: owner-dakota-truck@bent.twistedbits.net
[mailto:owner-dakota-truck@bent.twistedbits.net] On Behalf Of Eric Huff
Sent: Tuesday, July 06, 2004 12:48 AM
To: dakota-truck@dakota-truck.net
Subject: Re: DML: The dakota's pinging
> > 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
This archive was generated by hypermail 2b29 : Sun Aug 01 2004 - 00:46:14 EDT