[Gmecm] Stoich AFR and constants table

[Per Lonnborg]

Thanks Craig for answering,

I will try to be a little more clear:

My question regarding on-the-fly tuning was if all *ECM CONSTANTS* can be changed on-the-fly. Since they are constants I thougt that the 
ECM maybe just read some of these constants just once, perhaps when ignition comes on, or even just after a complete Power On/Off?

Seems to me a bit strange why the ECM would have routines to traverse all these constanst over and over when they normally are just, 
constants. On the other hand, MF#1 and MF#2 tables are in a way "constants" as well, but in this case the ECM has to lookup the right cell 
depending on which condition the motor is in.

I am NO expert on this, so please be patient with my thinkings! :-)

Why is ask is because of this: When I switched to the BIN with altered Stoich AFR the engine went extremely lean after about 5 minutes 
from startup. I also got the 44 O2 lean Flag, which I newer had before. I then switched back to my "normal" BIN (engine still running), but 
the very lean condition continued. Thats what I meant with my "bad" ALDL-readings.
(Mind you, this is not actually the on-the-fly tuning mentioned above, I use your "stacked BIN option with the 8-BIN switch)

Does any other know more about the Stoich AFR Constant and what it does?

I hope this will clear something about my thinkings!

/Per



>----Ursprungligt meddelande----
>Fr?n: craig at moates.net
>Datum: 2006-jul-03 06:25
>Till: "Per Lonnborg"<perlon at passagen.se>, <gmecm at diy-efi.org>
>?rende: Re: [Gmecm] Stoich AFR and constants table
>
>Per,
>
>You can use the TunerPro or TunerCat software to make changes on the fly without interrupting your ECM operation. No resets needed
>if you've got a decent emulator hooked up. There's several out there (I know I make a couple of em).
>
>I believe the stoich AFR will impact the target AFR which the ECM tries to achieve based on the switch points of the O2. It should
>impact both the learned fueling and the 'open loop' fueling. Anyone care to corroborate or refute?
>
>Not sure what you mean by bad readings on the ALDL. What did you see?
>
>Best regards,
>Craig Moates
>
>
>
>----- Original Message -----
>From: "Per Lonnborg" <perlon at passagen.se>
>To: <perlon at passagen.se>; <gmecm at diy-efi.org>
>Sent: Thursday, June 29, 2006 5:06 AM
>Subject: Ang: [Gmecm] Stoich AFR and constants table
>
>
>Hi again,
>
>I don?t seem to have got any answers regarding the (1) "Stoichiometric AFR" constant in 1227747/AMUR, and (2) my thoughts about
>changing
>constants values on the fly(driving)
>
>Perhaps Craig can help me out with the on-the-fly tuning part?
>
>/Per
>
>>----Ursprungligt meddelande----
>>Fr?n: perlon at passagen.se
>>Datum: 2006-jun-26 11:12
>>Till: <gmecm at diy-efi.org>
>>?rende: [Gmecm] Stoich AFR and constants table
>>
>>Hi!
>>
>>I have 2 questions:
>>
>>1. I am doing some testing with ethanol fuel (E85) in my ?747 TBI 350, and I wonder if anyone knows how the "Stoichiometric AFR"
>constant
>>affects the fuel metering?
>>
>>Does it for affect for example affect MF tables without not needing to alter the actual tables?
>>(I changed AFR from 14.70 to 9.90 which is the AFR for ethanol with 15% gasoline)
>>
>>
>>2. Can you change values in the Constants Table on the fly (driving), for example using Moates G2X TBI-Type Switching Adapter or
>Tuner
>Pro
>>Emulator, without upsetting the ECM or does it need to be resetted (power on/off)?
>>
>>It seems to me that when I switched to the 9.90 AFR .bin and then went back to the 14.70 .bin on the highway, I got totally wrong
>ALDL-
>>readings.
>>
>>
>>/Per Lonnborg
>>
>>350 TBI ?747 Chevy Monza
>>
>>Stockholm, Sweden
>>_______________________________________________
>>Gmecm mailing list
>>Gmecm at diy-efi.org
>>http://lists.diy-efi.org/mailman/listinfo/gmecm
>>
>
>
>_______________________________________________
>Gmecm mailing list
>Gmecm at diy-efi.org
>http://lists.diy-efi.org/mailman/listinfo/gmecm
>
>
>
>