Re: PI closed loop algorithm for 1227747 ECU?

[rr <RRauscher@nni.com>]

I think that the prop gain tables marked not-used, are intended for idle use. There are
other tables that are used, but are labeled slightly different. Check the areas starting
at: L84A2 and L84CF.

BobR.

Squash wrote:

> This is interesting as this exact thing is happening to me, popping on decel, and the others.  The
> idle I can tolerate, the BLM only moves a couple of points if it sits for a while.  It even gives
> a pop when the fuel c/o happens above 3000 rpm.
>
> I looked through the anht hac and the "proportional gains" table says it isn't used in anht, and
> the only other similar things I find start at 1e6.  Excuse my ignorance, but are these the
> equivalent values to the 747 ones you outlined below?
>
> Thanks,
> Squash
>
> --- Scott Lundahl <scott@lumenetics.com> wrote:
> > I've out of town and away from my e-mail, but I wanted to say thank you for
> > the information.  I've burned an EEPROM as follows:
> >
> > Prop tables at $4a8 & $4c7 have been reduced by 2/3 (since the
> > displacement, and hence fueling requirement, of my engine is about 2/3s of
> > the GM unit).  I have suspected the PI overshoot you mentioned for some
> > time (the O2 cross count frequency has been well over 10 Hz).
> >
> > Increased $48f int time delay table by 1.5 (since the the distance from the
> > TBI to the O2 sensor in about 50% longer than a stock GM V8 - those 4-2-1
> > headers are quite long)
> >
> > Set $2f9 to 1
> >
> > Set IAC table at $5c7 up + 1
> >
> > Enlean table at $3fa to $80 (go big block)
> >
> > So far it seems to run perfectly.  No trace of surging or other
> > badness.  Tailpipe backfire virtually eliminated (pleasant little burble
> > now)!  I haven't put on many miles, so things may converge to other values
> > where things don't work as well as time goes on (this has happened
> > before).  The idle still hunts a bit, so I'll work on that.  But it looks
> > good so far.
> >
> > Thanks again,
> >
> > Scott

<snip>

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