Question-Closed Loop Proportional Idle-Tables
Question-Closed Loop Proportional Idle-Tables Can someone explain to me how exactly the Closed Loop Proportional Idle tables work. I know that the proportional side will add or subtract the fuel depending on what the O2 sensors are reading.
The vs. Airflow Mode is a base adder, what exactly does this mean? What table is this base adder for?
The vs. O2 Error table is a multiplier, what exactly does this mean? What table is it a multiplier for?
Thanks in advance.
The vs. Airflow Mode is a base adder, what exactly does this mean? What table is this base adder for?
The vs. O2 Error table is a multiplier, what exactly does this mean? What table is it a multiplier for?
Thanks in advance.
I don't understand this real well, but the idea is that
the PCM wants a certain minimum density of O2 sensor
switching events for closed loop (believe it is time-
averaging crossings, not voltage-averaging samples?).
This bit of business here, is how it tries to force that -
if sensor shows lean, it bends mixture rich and vice
versa.
But there's some flies in that tasty jar of ointment,
one in particular being the gas lag when you get to
longer tubes (along with a slower electrical response).
That added lag can destabilize the trickery.
Multiplier tables seem to be used "logically" for the
most part, like adder()*multiplier() - a logical AND,
zero will make the adder "go away" and multiplier
of 1.000 will make the adder value apply. If the
table is all 0s and 1s you can bet on this kind of
mode. If you see a multipler table with "real" values
in a factory tune then there's some other scheme
at play.
If you hover over the table it ought to show a little
mini-help (very mini-) describing somewhat, and context
help might say a bit more. But the detail is not always
satisfactory.
You can also turn off the prop fueling and the natural
jaggedness of fueling (injector balance, etc.) can be
enough to run on (unless you get switching codes).
Turning it off might be good just to see what happens;
if it gets better in some way then you might suspect
the tube-length (transport delay) issues I mentioned.
I think I've had mine off for a long time, just because
I don't like things I don't understand, messing.
the PCM wants a certain minimum density of O2 sensor
switching events for closed loop (believe it is time-
averaging crossings, not voltage-averaging samples?).
This bit of business here, is how it tries to force that -
if sensor shows lean, it bends mixture rich and vice
versa.
But there's some flies in that tasty jar of ointment,
one in particular being the gas lag when you get to
longer tubes (along with a slower electrical response).
That added lag can destabilize the trickery.
Multiplier tables seem to be used "logically" for the
most part, like adder()*multiplier() - a logical AND,
zero will make the adder "go away" and multiplier
of 1.000 will make the adder value apply. If the
table is all 0s and 1s you can bet on this kind of
mode. If you see a multipler table with "real" values
in a factory tune then there's some other scheme
at play.
If you hover over the table it ought to show a little
mini-help (very mini-) describing somewhat, and context
help might say a bit more. But the detail is not always
satisfactory.
You can also turn off the prop fueling and the natural
jaggedness of fueling (injector balance, etc.) can be
enough to run on (unless you get switching codes).
Turning it off might be good just to see what happens;
if it gets better in some way then you might suspect
the tube-length (transport delay) issues I mentioned.
I think I've had mine off for a long time, just because
I don't like things I don't understand, messing.
Thanks jimmyblue for the response. I did hover over the table and read the description but that wasnt enough for me to understand. I am going to try and disable it to see what happens. Thanks
