LTFT-> PE
12-24-2006, 08:01 AM
#1
LTFT-> PE
As most of you guys know I've been OLSD tuning for awhile.
Yesterday I decided to turn on Closed Loop and see how it looks. Even though in OL by AFR error is +- 4% my LTFT's have fallen into +0-5%. Now if I understand this correctly, when I enter PE it will pull the LTFT into my PE fueling equation, thus explaining why I am pig rich in PE now.
Yesterday I decided to turn on Closed Loop and see how it looks. Even though in OL by AFR error is +- 4% my LTFT's have fallen into +0-5%. Now if I understand this correctly, when I enter PE it will pull the LTFT into my PE fueling equation, thus explaining why I am pig rich in PE now.
12-24-2006, 08:43 AM
#2
Open loop=no trimming, the only way to really get here is to turn the trims st and lt off and tune the VE via a wideband and afr correction
closed loop=trimming
Positive trims mean adding fuel because the pcm thinks its lean.
Why does it think its lean at wot? Look at B1 and B2 voltages tell me what you see.
closed loop=trimming
Positive trims mean adding fuel because the pcm thinks its lean.
Why does it think its lean at wot? Look at B1 and B2 voltages tell me what you see.
12-24-2006, 08:48 AM
#4
Hopefully the resident sponsor from HPT will jump in and explain a reason for differences in B1 B2 voltages when in PE and consequent trimming. I think the reason is from one side being leaner but have no proof other than stock 02 voltages, I get 100mv difference but KY yours is 200mv Ive never seen it that big before.
The solution to your problem is to turn the ltft's off and itll go away; makes sure to reset trims after making air adjustments or messing with trimming.
The solution to your problem is to turn the ltft's off and itll go away; makes sure to reset trims after making air adjustments or messing with trimming.
Last edited by 02sierraz71_5.3; 12-24-2006 at 09:14 AM.
12-24-2006, 09:25 AM
#5
Originally Posted by 02sierraz71_5.3
Hopefully the resident sponsor from HPT will jump in and explain a reason for differences in B1 B2 voltages when in PE and consequent trimming. I think the reason is from one side being leaner but have no proof other than stock 02 voltages, I get 100mv difference but KY yours is 200mv Ive never seen it that big before.
The solution to your problem is to turn the ltft's off and itll go away; makes sure to reset trims after making air adjustments or messing with trimming.
The solution to your problem is to turn the ltft's off and itll go away; makes sure to reset trims after making air adjustments or messing with trimming.
Even before the WB, B2 has always run a tad leaner than B1 in my truck.
12-24-2006, 09:40 AM
#7
Originally Posted by 02sierraz71_5.3
Open loop=no trimming, the only way to really get here is to turn the trims st and lt off and tune the VE via a wideband and afr correction
closed loop=trimming
Positive trims mean adding fuel because the pcm thinks its lean.
Why does it think its lean at wot? Look at B1 and B2 voltages tell me what you see.
closed loop=trimming
Positive trims mean adding fuel because the pcm thinks its lean.
Why does it think its lean at wot? Look at B1 and B2 voltages tell me what you see.
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12-24-2006, 11:22 AM
#10
Originally Posted by 02sierraz71_5.3
If youve got trims going on you arent in open loop