Timing Retard w/o knock & MAF oscillations

[Richard Wakeling]

Hi David,
You mentioned that Diacom used a wrong calculation for the MAT (Ambient
Air Temp). I was wondering whether or not you had figured out the
correct formula or why Diacom got it wrong? Any hints people?

Andrew Wakeling
David Cooley wrote:
> 
> At 03:32 PM 9/24/1999 -0400, you wrote:
> >In message <4.2.0.58.19990924105438.00955100 at 127.0.0.1>,David Cooley writes:
> > >At 10:45 AM 9/24/1999 -0400, you wrote:
> > >>In trying to understand some Diacom data. I'm seeing "knock retard" being
> > >>introduced, but No "spark control counts" being sensed..  Will the ECM
> > >>retard the timing when the table jumps from LV8 column to LV8 column and
> > >>the requested advance decreases in this column jump?
> > >>
> > >Nope... Would just show as a different value in the timing advance data...
> > >retard is when it pulls timing due to knock and it's modifying whatever
> > >value is in the timing table.
> >
> >So then the original question goes back to, "How can Knock Retard be
> >introduced by the ECM, when there are no spark control counts"?
> 
> I;ve seen both items happen... spark control counts increasing with no
> displayed knock retard, and knock retard with no spark control
> counts...  Usually it's caused by a flaw in the Diacom software... My buick
> used to show ambient temp as 65 degrees when it was 65 degrees, but at 100
> degrees it had only increased to 75...   The raw ALDL data converted to the
> proper values though.  there were several other parameters that were way
> off in my Diacom data...
> ===========================================================
> David Cooley N5XMT Internet: N5XMT at bellsouth.net
> Packet: N5XMT at KQ4LO.#INT.NC.USA.NA T.A.P.R. Member #7068
> We are Borg... Prepare to be assimilated!
> ===========================================================