I’m just wondering if any other Cali EV owners know what their CO trim was set at? When I got in to the ECU via guzy diag mine was set at +196 which is the maximum! I’d be interested to know what others have discovered when they have looked? I now have mine set at 45. Also does the CO trim only really affect the idle fuelling and does the ECU map differently as it goes up through the revs.?
I got this info from somewhere:-
Co Trim
What does CO TRIM setting do in our Moto Guzzi? I have MG Quota 1100ES and I can change CO TRIM via guzzidiag, but what does CO TRIM affect to?
I know it affects to a mixture richness but I don’t know:
- if it works only in the particular revs? Or on the whole range of revs? - if it works only for one cylinder? Or for both? - can it be treated like a way to make a richer or leaner mixture (in the whole range of rev)?
Idle fuel trim affects the low rpm mixture in the same way as the pilot/idle circuit in a carburetor. Up to about 1/4 throttle, quite a lot, fades away after that.. The range displayed -128 to+127 with 0 being a valid integer. 256 increments. My V11 with Stucci crossover and MIVV cans runs best at +20 or so. Was set at -10 and stumbled and bucked at a steady 3-3500 rpm with Mistrals and stock crossover. A bit worse with the new exhaust setup. Hot days above 90F may need +30 to banish the surge depending on your engine breathing
CO trim adds a fixed time to the real-time injection pulse-width. This is added across the entire RPM range. A CO trim of +1 adds 10 microseconds to the real-time pulse. A value of +10 adds 100 uS. Conversely, -10 will subtract 100 uS.
The affect appears non-linear because it’s is the same amount for any given TPS/RPM value. For example, at idle, the real-time pulse-width may be 2500 uS. If you set CO at +10, the pulse-width becomes 2600 uS. If the pulse-width is 8000 uS at 7000 RPM, the pulse will now become 8100 uS. This is a 4% increase at idle and 2.3% increase at 7000 RPM. Ergo, the affect appears non-linear and has the greater affect at idle.
I set it about like a carb idle screw.
Set it a bit too rich. Then lean it out until the idle starts to drop. Richen it back up until the idle speed returns to normal. That is where I stop. For EPA numbers, the setting is going to be a slight RPM drop.
You should be pretty close to zero. I’ve never run into one yet that benefits from more then a slight tweak.
If you do have an analyser, for the 8V, 5-7% CO, for any 2 valve head, 3-5% CO
in addition to above there is a factor applied to the CO value, stored at $B7B3 ($B793 for Quota 1100). Value range is 0-255. $80 is equal to factor 0, $40 corresponds to 0.5 and $C0 to 1.5.
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