7747 spark control questions.

[Shannen Durphey]

Kevin R wrote:
> 
> In trying to understand this a little more I have a few questions and
> suppositions. Need you guys to yea, nea or just plain shoot hole thru them
> for me..
> Thanks.
> 
> Initial spark advance: Lets the ECM know what the dist is set at physically,
> but all the bins I've checked seem to be set at 0.. does this mean those
> application(all trucks) dist are set at 0 physical from the factory or have
> I got what this does wrong?
Many trucks are set at zero.  Anything other setting is an exception
rather than the rule.
Increasing initial spark reduces overall timing.
Shannen

> 
> Warm Bias (main bias in TC): Just so neg advance can be applied in spark
> table as pos numbers!? Why is this necessary? If the dist is set at 0
> physical why would neg numbers be needed in main table?
> 
> Cold Bias: So neg numbers can be applied as pos numbers in coolant(engine
> temp) compensation table. I can see this, but is this table(would think so)
> always active?  Then it would seem both Cold and Warm bias' are active all
> the time!?
> 
> PE spark: Trying to compare this to a function in a mech dist(I know the
> elect always for more specific spark control) the only reason I can see for
> this is either to use lower numbers in main table for emissions reasons and
> add it back when needed for acceleration or like the PE enrichment to get
> some spark going faster than would happen waiting for a value lookup???
> 
> Kevin R
> 
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