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Originally Posted by BlackSS
Ok, today I've been playing around all day with the VE settings. I set the Maf fail freq down and it seems to be running rough like you said. I've been copying and pasting(using add function since the numbers are all in the negatives) the LTFT % histogram. I've done it about 8 times, driving between 15 to 30 minutes a pop. It doesn't seem to be doing anything for the LTFT. I've made sure when I copy and paste everything works out correctly and it does. I am just wondering do I keep doing this over and over untill it's right? My LTFT always seems to go back to -14.1 eventually no matter what. In the histogram at an idle each time shows between -12 and -18. Keep in mind I've done this over and over so I figured it would be getting close by now. Am I just wasting my time or do I keep doing it? I'm not using the original file, I keep using the one from the last flash just to clarify. Thanks.
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You should be SUBTRACT from the VE tables to compinsate for a negative FT value. Clear your VE back to stock.
Couple of things I don't think you are doing that you should.
1) create a custom PID that is the LTFT + STFT value. I called mine L/STFT.This will give you a more accurate reading then just one or the other.
2) Create a custom Histogram that monitors the L/STFT value instead of just the Long or just the short.
3) On your custom histogram, don't copy any cells with less then 40 (some would say 400, but our cars learn fast) hits. This is not enough data for calculating.
4) Also on your custom histogram, put a filter on that only looks at cells with a TPS < 80%. When you go WOT (or near it), the car goes into PE mode, which disables all your trims anyways. Try to avoid going WOT when doing VE/MAF tuning anyways. It just isn't helpful.
5) Disable DFCO. Again, the FT's are disabled in DFCO. Just set the ECT enable temp to 250 degrees (just to keep it from being enabled). When test driving, try to keep part throttle all the time. I use cruise control on hilly roads. It hits lots of cells. Make sure you use all gears to get all rpm ranges. Turn back on DFCO when you are done tweeking it, as it saves a ton of gas.
6) If you end up with a L/STFT value of -14 for a given cell, SUBTRACT 7% (half of 14) to that cell on the ve table. BABY STEPS is the name of the game. If it is a postitve trim value, ADD from the VE value by half that percent. Remember a negative FT value is better then a positive. A range of zero to -5 is better then 0 to +5. If it is negative the car is taking fuel away. That is better then it having to add fuel, although when all sensors (mainly your O2, MAP, and MAF) are working right, it shouldn't matter.
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== NUMBER 7 VERY IMPORTANT! ======================
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AS SOON AS YOU CHANGE ANY VE VALUES, GO TO VCM SCANNER DIAGNOSTICS AND RESET FUEL TRIMS WITH THE CAR IN THE ON POSITION BUT NOT YET STARTED. (I think that is why your values never changed)