will commit murder over tuning issues!
11-09-2004, 03:59 PM
#41
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Originally Posted by TurboBerserker
First -- did you back out the FMU? 5.2 is still a little rich. Try 5.29. 1020mv is about 100 mv too much. Shoot for 900-920mv for now, but you really need to get a wideband reading on your truck to know the sweet spot.
Also, reset your LTFTs and go drive around for a while trying to put the truck through a bunch of engine loads and rpms (without going WOT or stabbing the throttle). After that you're LTFTs will be changed from reseting the IFR. Then try the WOT run.
My LTFTs are 0 to -3 for all cells in closed loop, but I took the time to set the IFR correctly and then tune my VE table using speed density tuning. LTFTs at WOT will lock at zero (anytime you go into open loop).
Also, reset your LTFTs and go drive around for a while trying to put the truck through a bunch of engine loads and rpms (without going WOT or stabbing the throttle). After that you're LTFTs will be changed from reseting the IFR. Then try the WOT run.
My LTFTs are 0 to -3 for all cells in closed loop, but I took the time to set the IFR correctly and then tune my VE table using speed density tuning. LTFTs at WOT will lock at zero (anytime you go into open loop).
, BEFORE when I had the IFR set at 4.8 the FT'S were steady @ -2% to 0 @ part throttle driving, now that I reset them to 5.2 they are setting @ +9%. so increasing them(ifr) would make it run even leaner causing the to add even more fuel. On my version of edit you decrease the ifr if is lean & increase the ifr rates if it is overly rich. I understand how to adjust FT values, I have tuned this truck & several others with a wideband. Wideband is no longer availible, I have a strong suspesion that I am washing the O2's with gas causing it to bang out. I still have not heard from anyone with a blown 6.0 what pe tables they are running. 
11-09-2004, 08:26 PM
#43
IFR is just g/sec... 4.7 in the IFR equates to a 37 lb/hr injector.
It was common practice to adjust LTFTs by movng the IFR table because no one had a handle on VE yet. It's best to just set your IFR to the correct number and adjust your VE table (since your VE is what is so changed).
If you think about it, the IFR way is trying to trick the PCM into the proper fueling by telling it the injectors are a different size so it does its fuel calcs based on the wrong number. In my experience this practice leads to unstable, unpredictable tunes. Kinda like what you are experiencing...
It was common practice to adjust LTFTs by movng the IFR table because no one had a handle on VE yet. It's best to just set your IFR to the correct number and adjust your VE table (since your VE is what is so changed).
If you think about it, the IFR way is trying to trick the PCM into the proper fueling by telling it the injectors are a different size so it does its fuel calcs based on the wrong number. In my experience this practice leads to unstable, unpredictable tunes. Kinda like what you are experiencing...
11-10-2004, 09:44 AM
#44
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Originally Posted by TurboBerserker
IFR is just g/sec... 4.7 in the IFR equates to a 37 lb/hr injector.
It was common practice to adjust LTFTs by movng the IFR table because no one had a handle on VE yet. It's best to just set your IFR to the correct number and adjust your VE table (since your VE is what is so changed).
If you think about it, the IFR way is trying to trick the PCM into the proper fueling by telling it the injectors are a different size so it does its fuel calcs based on the wrong number. In my experience this practice leads to unstable, unpredictable tunes. Kinda like what you are experiencing...
It was common practice to adjust LTFTs by movng the IFR table because no one had a handle on VE yet. It's best to just set your IFR to the correct number and adjust your VE table (since your VE is what is so changed).
If you think about it, the IFR way is trying to trick the PCM into the proper fueling by telling it the injectors are a different size so it does its fuel calcs based on the wrong number. In my experience this practice leads to unstable, unpredictable tunes. Kinda like what you are experiencing...
I've changed values at high as plus/minus 10, with very little change in LTFT's (after resetting them). I can feel a SOTP, or hear a difference in the way the motor runs, but the results just don't show up for me in the scanner.
I've done small tweaks to bring LTFT numbers down 2 points, and I think I had to use values of 4 or greater in the VE table.
If I were to bring my IFR back to stock, my VE numbers would be way the hell up there, I think near the ceiling of acceptable values... (120%?)
11-10-2004, 10:18 AM
#45
Originally Posted by marc_w
I agree... but at least on my truck, modding the VE table doesn't give results NEARLY as well as the IFR table does.
I've changed values at high as plus/minus 10, with very little change in LTFT's (after resetting them). I can feel a SOTP, or hear a difference in the way the motor runs, but the results just don't show up for me in the scanner.
I've done small tweaks to bring LTFT numbers down 2 points, and I think I had to use values of 4 or greater in the VE table.
If I were to bring my IFR back to stock, my VE numbers would be way the hell up there, I think near the ceiling of acceptable values... (120%?)
I've changed values at high as plus/minus 10, with very little change in LTFT's (after resetting them). I can feel a SOTP, or hear a difference in the way the motor runs, but the results just don't show up for me in the scanner.
I've done small tweaks to bring LTFT numbers down 2 points, and I think I had to use values of 4 or greater in the VE table.
If I were to bring my IFR back to stock, my VE numbers would be way the hell up there, I think near the ceiling of acceptable values... (120%?)
11-10-2004, 10:52 AM
#46
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Originally Posted by TurboBerserker
You need to tune with the MAF unplugged. Believe me, until I tried that, I kept saying VE Tuning was worthless... I could never get any results at all. Now, I am the SD tuning poster child...
I missed out on the early 'discovery' of SD tuning, and I've been REALLY out of the loop. I'll definitely look into it and give it a try.
I'd LOVE to get my IFR's back to stock... I watch my MPG readings in the DIC like a hawk. I've recently found out they're a little out of wack.
11-10-2004, 11:30 AM
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Originally Posted by TurboBerserker
I swear by it. The truck runs much better now, SOTP, as well. Far fewer funny little inconsistencies and issues.
https://ls1tech.com/forums/showthread.php?t=219947
11-10-2004, 11:33 AM
#49
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Originally Posted by TurboBerserker
I swear by it. The truck runs much better now, SOTP, as well. Far fewer funny little inconsistencies and issues.
I posted a number of questions in an SD thread I caught on the site... would you be able to answer any of them for me?
https://ls1tech.com/forums/showthread.php?t=219947
11-10-2004, 11:47 AM
#50
I use a different method than the ones outlined by WS6snake-eater.
Here's my method:
1) unplug the MAF (and for us 5 wire MAF guys -- IAT included -- that means cutting the yellow wire in the MAF plug -- the MAF sender wire)
2) Reset your LTFTs and log, trying to hit every cell in the LTFT histogram in the scanner (if you are going to plug in your MAF again you can ignore those cells over 4000 rpm as they are purely driven by the MAF anyway, according to the HPT gurus -- I personally did them all anyway as I wasn't planning on using the MAF anymore)
3) calculate the change to each VE cell using this formula:
LTFT value + STFT value = change to the VE value
You will run into cases where the LTFT is negative and the STFT is positive -- doesn't matter, just add whatever signed values you see and add the result (again whatever sign) to the VE in that cell. This gets you pretty close. You may need to repeat 2 and 3 two or three times.
4) Fine tuning: disable your LTFT learning (by setting the LTFT learn enable min temperature to 284 or the same as the max setting -- You can also turn it off in HPT VCM scanner, but mine kept coming back on every 15 minutes or so...), reset your LTFTs and relog, but this time ignore the LTFT histo (since its turned off) and focud on the STFT histogram
5) calculate the VE adjustments by adding whatever STFT value you see in any cell to the VE table value. You may need to repeat 4 and 5 two or three times.
6) re-enable your LTFT learn, plug in your MAF,
7) scale the MAF to get your trims back to where they were with the MAF unplugged -- you're done
I think those steps covered all your questions, but I'll help however I can. Ask away.
Here's my method:
1) unplug the MAF (and for us 5 wire MAF guys -- IAT included -- that means cutting the yellow wire in the MAF plug -- the MAF sender wire)
2) Reset your LTFTs and log, trying to hit every cell in the LTFT histogram in the scanner (if you are going to plug in your MAF again you can ignore those cells over 4000 rpm as they are purely driven by the MAF anyway, according to the HPT gurus -- I personally did them all anyway as I wasn't planning on using the MAF anymore)
3) calculate the change to each VE cell using this formula:
LTFT value + STFT value = change to the VE value
You will run into cases where the LTFT is negative and the STFT is positive -- doesn't matter, just add whatever signed values you see and add the result (again whatever sign) to the VE in that cell. This gets you pretty close. You may need to repeat 2 and 3 two or three times.
4) Fine tuning: disable your LTFT learning (by setting the LTFT learn enable min temperature to 284 or the same as the max setting -- You can also turn it off in HPT VCM scanner, but mine kept coming back on every 15 minutes or so...), reset your LTFTs and relog, but this time ignore the LTFT histo (since its turned off) and focud on the STFT histogram
5) calculate the VE adjustments by adding whatever STFT value you see in any cell to the VE table value. You may need to repeat 4 and 5 two or three times.
6) re-enable your LTFT learn, plug in your MAF,
7) scale the MAF to get your trims back to where they were with the MAF unplugged -- you're done
I think those steps covered all your questions, but I'll help however I can. Ask away.