Closed Loop Proportional Idle
Closed Loop Proportional Idle Has anyone learned anything about this??? I searched and searched and everyone seems to be really stumped about it...
I wanna know if adjusting these settings can improve rich/lean conditions at idle...
I wanna know if adjusting these settings can improve rich/lean conditions at idle...
FormerVendor
Joined: May 2004
Posts: 152
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Originally Posted by txhorns281
Has anyone learned anything about this??? I searched and searched and everyone seems to be really stumped about it...
I wanna know if adjusting these settings can improve rich/lean conditions at idle...
I wanna know if adjusting these settings can improve rich/lean conditions at idle...
It depends.
The proportional tables determine how much fuel to add or remove to make the O2 sensors switch from rich to lean (and vice versa).
Think of it as a thermostat for heating and air conditioning to keep your room at 70 degrees. It has more to do with closed loop stability than making the engine run rich or lean.
The rich lean tables determine where the AFR at closed loop should be.
The proportional tables determine how much to quickly add/remove to get there.
When the VCM makes a change, it expects to see the change.
That is what the integrator delay table is for. If the change does not happen below those table times, the VCM will add or subtract fuel to try and center itself on the rich lean tables.
Most of the time you will not need to adjust these tables unless your race car has a radical cam and is letting air into the exhaust to show a false lean condition. Or you have increased the injector size substantially.
Ken
I changed the O2 mV switch points in order to lean out the target AFR slightly and it worked. I started playing around with the proportional table in order to stabilize the AFR better. It was more of a hit or miss thing. Watch the O2 mV in scanner and determine how the changes increase or decrease the overshoot. You want to see the keep O2s flipping high and low without too much clipping. Perhaps clipping more low for higher AFR and clipping high for lower AFR. Hope that made some sense.
Originally Posted by SSpeedracer
I changed the O2 mV switch points in order to lean out the target AFR slightly and it worked. I started playing around with the proportional table in order to stabilize the AFR better. It was more of a hit or miss thing. Watch the O2 mV in scanner and determine how the changes increase or decrease the overshoot. You want to see the keep O2s flipping high and low without too much clipping. Perhaps clipping more low for higher AFR and clipping high for lower AFR. Hope that made some sense.
Originally Posted by wait4me
the lower the lobe seperation the more it is affected, like 108 ls or 110 114 and higher normally arent a problem.
