Timing Retard w/o knock & MAF oscillations

[Ward]

On Fri, 24 Sep 1999 15:55:46 -0400, 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!
> ===========================================================
> 
I don't thnk the falw is in the Diacom SW, its in the GM reporting method.
the older TPI's reported some funn stuff that didnt happen, the Early BB
truck w/4l80e also miss-reported spark advance and AFR.

Ward




________________________________________________________________
Get FREE voicemail, fax and email at http://voicemail.excite.com
Talk online at http://voicechat.excite.com