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Old 06-07-2006, 07:45 PM   #29
John Wayne Toilet Paper
Member#: 7327
Join Date: Jun 2001
Chapter/Region: NWIC
Location: Seattle, WA
2008 Mazdaspeed3
2006 Wrangler Sport


Originally Posted by silver arrow
How long does knock correction take? The engine just knocks away until it feels like correcting it?
completely different topic. Knock correction is an instaneous thing that happens in response to detected knock and corrections linger for awhile until the ECU feels it can push it back again.

With AF Learned Trims, that is not something that can just be corrected immediately because it is so much more variable, thanks to effects from tip-in and lift-off. The ECU makes instantaneous corrections to AF in closed loop and then remembers a running average so to speak of those corrections for every single MAFv it has encountered and starts to modify the learned values.

The reason it's better to reset the ECU when this takes place is because resetting the ECU also takes the IAM back to the standard initial value of 0.5 (unless you or your tuner has changed it) which means you're not running full advance during this afr-uncertain time.

Also, experience has shown that Learned corrections which are made in closed loop DO get applied to open loop as well, but the mechanism by which that happens is not clear to me yet. A lot depends on the MAF sensor and the stored corrections so again... why chance it when you can just play it safe?
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nhluhr is offline   Reply With Quote