[Gmecm] Adjusting 7730/$8D for larger cam

[JohnsHome]

Yes, I would start there and see if it responds.
My final values that I run now are actually 0.050 lower.
I found going farther made matters worse so go in small steps after 0.035
less.
You still have the stock settings of AUJP.
The numbers at the end are my current values.
Cleaned up the idle (mostly) and got rid of the smelly exhaust.
> 0.60V at 496 (Idle O2 Rich/Lean Threshold Fast)        Mine 0.539 ($7C)
> 0.60V at 497 (Idle O2 Rich/Lean Slow Zero Error Upper) Mine 0.539 ($7C)
> 0.56V at 498 (Idle O2 Rich/Lean Slow Zero Error Lower) Mine 0.513 ($74)
I still highly recommend getting the 3 wire o2. You could drop out of CL
when idling very easily.

My closed throttle SA is at 28*, my motor like the advance there. Gets real
rough when lower.
Check that you have "blended" a bit of that coming off idle with the values
in your main table.
Could get some stumbles there if the change is too drastic.
Wish this snow would go away!!!
John

> -----Original Message-----
> From: gmecm-bounces at diy-efi.org [mailto:gmecm-bounces at diy-efi.org]On
> Behalf Of Clair Davis
> Sent: Friday, February 02, 2007 11:44 PM
> To: gmecm at diy-efi.org
> Subject: Re: [Gmecm] Adjusting 7730/$8D for larger cam
>
>
> John,
> Question regarding the O2 constants you mentioned...
>
> In the Constants/Scalars section, I've got:
> 0.60V at 496 (Idle O2 Rich/Lean Threshold Fast) 0.539  ($7C)
> 0.60V at 497 (Idle O2 Rich/Lean Slow Zero Error Upper) 0.539 ($7C)
> 0.56V at 498 (Idle O2 Rich/Lean Slow Zero Error Lower) 0.513 ($74)
>
> Are you saying to knock them all down by 0.04 - to 0.54, 0.54,
> and 0.52?  I
> haven't done that yet, but I can before I burn again.  I bumped the idle
> spark advance at 800rpm up to 24.96* from 20.04* in the Closed
> Throttle vs.
> RPM table.  That's the same as the 1200rpm point, not a big bump, and this
> engine likes idle advance.
>
> With some luck, I'll get to try this out tomorrow, and see what the BLM's
> look like as well.
>
> On a semi-related note, what are some thoughts on saving versions
> of bins to
> help track progress?  I've got very few changes at this point, so
> I've been
> keeping essentially a single file so far.  I can see how I'll
> need multiple
> files in the very near future, and I'd like to keep up with what has been
> changed.  I'm thinking date-stamp-type file names, but that can get
> ungainly, and the XDF would have to be changed at the same time.  Maybe no
> biggie, if I keep the date stamp in a directory name.  There must be some
> tidier ways, though.
>
> Thanks again,
>
> Clair
>
> ----- Original Message -----
> From: "JohnsHome" <JohnsHome at wideopenwest.com>
> To: <gmecm at diy-efi.org>
> Sent: Thursday, February 01, 2007 9:32 PM
> Subject: RE: [Gmecm] Adjusting 7730/$8D for larger cam
>
>
> > I would suggest upping your idle timing a bit to see if that helps.
> (closed
> > throttle table L81FD-8209)
> > Removing about 40mV from the o2 constants may help as well.
> > They are at L8496 thru L8498 locations. Will get the smell of
> unburnt fuel
> > to get better as well.
> > Not knowing what cam you are running, although it sounds like
> its mid 220
> > range from the description I'm not sure what else to suggest. Hopefully
> you
> > are running a heated o2. If not, get one for sure.
> > Idle will probably need to be around 700-800 rpm.
> > There is a hard code idle limiter in AUJP if that is what you
> are running.
> > It can be increased by changing BOTH values to be the same at locations
> > L426C & L4270.
> > these are in the code and will need to be added to your XDF or just done
> in
> > the hex editor.
> > They are single byte, RPM = 6400/255 = 25 rpm increments.
> > For 1000 RPM max idle you would use a value of $50
> > These have helped me out with my 224/230 roller 350. My idle is
> at 58Kpa @
> > 800 RPM.
> > HTH
> > John
> >
>
>
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