another LTFT thread..
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From: Portsmouth, VA
another LTFT thread.. I've been reading that i dont need to touch my STFT's. I have stock cam and ported heads and am trying to maximize my WOT fueling for track runs. I'm trying to figure out where I am/will go wrong and if I'm going about this the correct way.
questions...
-I've disabled the MAF fail frequency in HPT to 0hz and don't get a SES light after i rewrite calibration. MAF is still plugged in. reset fuel trims. then go log.
-I log in my Histograms and try to go WOT and fill in the most of the graph I can driving about 40 miles or so.
-after my log I scroll over my log graph to fill in the cells and find out my LTFT's are something like +10 at 100-105kpa.
-I go to my VE table Editor and add 10 )or whatever to all the corresponding cells and reload the tune.
- do i need to reset my fuel trims before i go and relog?
-Should I be commanding closed loop while I'm relearning my fuel curves.
-and do i need to disable DFCO, whatever that is while I'm doing all this?
last but not least when i feel everything is in line I set my MAF fail frequency back to 14000 and reflash my PCM and I should be set??
I've done this method and one day getting +10 LTFT's, the next day i was getting +9 LTFT's again!!!!! Would that explain that I did nothing at all??
Thanks for any help guys.
questions...
-I've disabled the MAF fail frequency in HPT to 0hz and don't get a SES light after i rewrite calibration. MAF is still plugged in. reset fuel trims. then go log.
-I log in my Histograms and try to go WOT and fill in the most of the graph I can driving about 40 miles or so.
-after my log I scroll over my log graph to fill in the cells and find out my LTFT's are something like +10 at 100-105kpa.
-I go to my VE table Editor and add 10 )or whatever to all the corresponding cells and reload the tune.
- do i need to reset my fuel trims before i go and relog?
-Should I be commanding closed loop while I'm relearning my fuel curves.
-and do i need to disable DFCO, whatever that is while I'm doing all this?
last but not least when i feel everything is in line I set my MAF fail frequency back to 14000 and reflash my PCM and I should be set??
I've done this method and one day getting +10 LTFT's, the next day i was getting +9 LTFT's again!!!!! Would that explain that I did nothing at all??
Thanks for any help guys.
LTFT's at WOT are transfered from learned trims during cruise. Your O2 sensors are crap at WOT and have no clue what's going on. You need a wideband O2 for that. Sounds like you need to read the stickies/tuturials over again.
also, if you redo your VE and then reenable MAF, you're gonna be mostly running of MAF, which is oblivious to the new settings. you gotta recalibrate it to match the newly reshaped VE.
Also note, if your running a 1999 PCM (like your sig implies), you have a secondary VE table.
If you just adjusted your Primary VE, you wouldn't see the effects after flashing with the new adjustments.
I made this mistake for several flashes, oops.
If you just adjusted your Primary VE, you wouldn't see the effects after flashing with the new adjustments.
I made this mistake for several flashes, oops.
Thread Starter
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iTrader: (8)
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From: Portsmouth, VA
so My secondary table is just a mirror of my primary? the same changes need to be done on that table too as the primary? when is the PCM switching between tables?
thanks for the help guys.
thanks for the help guys.
Originally Posted by GregWS6&z28
so My secondary table is just a mirror of my primary? the same changes need to be done on that table too as the primary? when is the PCM switching between tables?
thanks for the help guys.
thanks for the help guys.
Dont even try to do any WOT tuning unless you have a wideband in the car. Its worthless. Without the wideband the only tuning you want to do is closed loop.
Also keep in mind that when you turn the MAF back on that the car will provide fueling almost solely on the MAF, so you will have to tune the MAF table as well.
Also keep in mind that when you turn the MAF back on that the car will provide fueling almost solely on the MAF, so you will have to tune the MAF table as well.
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If you don't have a WB, couldn't you get an idea of the AFR by watching the NB02 voltages? I know that the WB02 is the best way to do it, but would the NB02's get you in the ball park? Just asking because I'm trying to learn this stuff too. 
Originally Posted by LuvmyC5
If you don't have a WB, couldn't you get an idea of the AFR by watching the NB02 voltages? I know that the WB02 is the best way to do it, but would the NB02's get you in the ball park? Just asking because I'm trying to learn this stuff too.
