First-time AutoVE, LOTS of questions...

[Mr. P.]

Hi - I finally have gone through the AutoVE tutorial and now having done the process a couple times I have lots of questions.

Vehicle is 2003 Silverado SS, factory stock 6.0L with CAI, 1-7/8" American Racing Headers longtubes, and 3" Corsa Touring catback; truck is all-wheel drive with 4-spd automatic and 4.10 rear gears.

Here is a screen capture from EFILive Scan tool log, *after* going through AutoVE once and applying the BENS to my original tune, I have NOT done the AutoMAF correction yet, in this 3-second log I stepped-down in the throttle at about 30mph and I let the truck go WOT through 1st and 2nd gears:
http://www.allensrodeophotos.com/Steve/EFILive/Scan-SC1.gif

Questions:

1) Why am I getting KR (red line at bottom)? I think it is related to the MAF line (orange line) like the PCM is pulling timing because there was a sudden change in MAF reading??? Is this burst-knock? Where do I look to address this?

2) Compare the commanded AFR (top white line) with the wideband reading (light-yellow line next to it) - the PCM commanded a 12.0:1 AFR but the wideband didn't even flinch??? I expected the wideband to follow commanded AFR but it doesn't, any ideas why?

3) The LTFT's during normal cruise are -3.9 and -2.3; I expected them to be ZERO after applying the BENS from the AutoVE session? And LTFTs went to ZERO during WOT, and then a blip to the positive??? I am not understanding (yet) the behavior of the LTFTs here.

4) In a perfect world shouldn't DYNCYLAIR and CYLAIR be equal? (they aren't in several places)

5) Looking at the MAP log, it fluctuates from 99 to 95 kpa while the throttle is WOT, is this normal? I would think once you went WOT the MAP would hit 100 and stay there, ideally...

6) Is it normal for the WB readings to fluctuate as much as they do? During cruise (before WOT) the commanded AFR 1s 14.58 but the WB fluctuates everywhere between 14.58 and 15.72, the average is 15.0:1 and to me this is a lot leaner than the PCM intends.

7) On the driving process itself, my best friend uses HPT and he wigged when he saw that I was driving over 4000-RPM and over 80% throttle while AutoVE tuning - should I be worried and keep logging to under these limits?

On the good news, I have already gained 1-mpg in ecomony, the truck went from 14-mpg to 15-mpg.

I can see I need to rework the CAI to get the IATs down, they were almost 20-degrees over ambient all the time. After getting the KR issue nailed down I am also going to raise the 1-2 shift point to 6000-6100 as well.

I am going to read Mr. Prick's links before I head out again to do more driving.

Mr. P.

[mr.prick]

My 2¢


1) Why am I getting KR (red line at bottom)? I think it is related to the MAF line (orange line) like the PCM is pulling timing because there was a sudden change in MAF reading??? Is this burst-knock? Where do I look to address this?
Too much spark, aggressive knock settings, lean AFR ect.


2) Compare the commanded AFR (top white line) with the wideband reading (light-yellow line next to it) - the PCM commanded a 12.0:1 AFR but the wideband didn't even flinch??? I expected the wideband to follow commanded AFR but it doesn't, any ideas why?
PE timer delay, add fuel to the VE table see if that changes.


3) The LTFT's during normal cruise are -3.9 and -2.3; I expected them to be ZERO after applying the BENS from the AutoVE session? And LTFTs went to ZERO during WOT, and then a blip to the positive??? I am not understanding (yet) the behavior of the LTFTs here.
I suggest tuning with LTFTs for LTFT areas and WBO2 for WOT. :lookaround:


4) In a perfect world shouldn't DYNCYLAIR and CYLAIR be equal? (they aren't in several places)
They won't be perfectly inline with each other.


5) Looking at the MAP log, it fluctuates from 99 to 95 kpa while the throttle is WOT, is this normal? I would think once you went WOT the MAP would hit 100 and stay there, ideally...
I get this too at certain altitude and certain MAP and RPM areas


6) Is it normal for the WB readings to fluctuate as much as they do? During cruise (before WOT) the commanded AFR 1s 14.58 but the WB fluctuates everywhere between 14.58 and 15.72, the average is 15.0:1 and to me this is a lot leaner than the PCM intends.
It won't be perfectly steady, wild AFR flux can be from:
LTFTs not right, injector scales/offsets not right
WBO2 placement can be a culprit as well,
I installed mine after the ypipe (fbody) because having it in one side of the
the ypipe gave me AFR swings that would make BEN over/under adjust.


7) On the driving process itself, my best friend uses HPT and he wigged when he saw that I was driving over 4000-RPM and over 80% throttle while AutoVE tuning - should I be worried and keep logging to under these limits?
:confused: only if AFR is lean, you are not WOT all the time are you? :shock:

[dfe1]

5) Looking at the MAP log, it fluctuates from 99 to 95 kpa while the throttle is WOT, is this normal? I would think once you went WOT the MAP would hit 100 and stay there, ideally...
Mr. P.
With a naturally aspirated engine, MAP can never exceed ambient barometric pressure. If uncorrected barometer is 97, that's the maximum pressure that will exist inside the intake manifold. Additionally, any flow restriction will decrease MAP, so you may never see more than 94 or 95 kPA even if the barometer is above that. Notice that your MAP reading are lowest where RPM and air flow are highest-- right before the 1-2 shift. That's because the impact of an induction system restriction becomes more pronounced as air flow increases.