I have a feeling I am going to wear this section out with questions SD tuning this dang thing.

I have run into a very badly off area of the VE. Verified twice by a couple runs into it. Basically a light throttle, 1st gear pull to about 5200 need to go to about 6200 before I'm done. Seeing 35-45% AFR error Sanity check please.... I know I need to move this but want someone with more experience to say yes you need to.

Here are a couple screen shots of what I am seeing.

Original VE table I started with.


My last histogram with 5 cell counts... did not want to see much of this.


VE table after pasting in the error. How the heck do you smooth THAT in?

 

Holy crap I am not the expert, but you need to change it. The wierd thing is that you are tunning in SD mode so you have less of a chance of electronic failures screwing with results. Are you tunning with a WB? maybe something is failing with the WB? Those last five cell counts were done on park and reving the engine right?

 

thats why i love EFI Lives's Auto Tuning...try another run again..did you add any perctage to the ve table before you started to correct it?? i did a speed density tune to day on a pretty much stock truck today and i added 20% at first because it was so lean in SD and i did not have to change much from there..

 

Yes I am tuning with a WB. The WB is fine. I was in first gear on an entrance ramp to an Interstate, slow part throttle run to 5200 rpm.

 

But how do you know the WB is fine. Can you compare that to just the Narroband and see if you see the same spike. I am just thinking it is something that went crazy for a few moments and is not correct.

But I would do the same thing again and see what happens (as far as going on ramp again). It might have not happened but did you see any KR inthose cells. if you did than all there is left to do is add then.

 

thats DFCO dont worry about the trims when you let off the throttle, also you'll find that you can just raise the area after it peaks up sort of like it hits 4500 then so rolls over across the rest of the rpm range, that big dip after 4k rpms and not at wot is not correct, most people dont bother with it because its an area rarely seen.

 

definitly looks like dfco is possibly still on...some calibrations have more dfco then others...also 5 cell hits for your ve table is definitly not enough to think the data is valid. Try 25 or 50 hits & get a nice long drive in.

 

I've duplicated the area twice. Nearly identical results. I've started tuning the VE table 3 times. 1st I added 15% fuel. It was way rich and I screwed it up so next time around went 7%.

I saw your post about doing a SD tune on the dyno in like 5 hours. I can only dream. I am beginning to understand it but don't have the experience yet. Auto tuning this would be sweet! I see AutoTune verbiage in HPT but not enabled yet.

 

I was watching the WB gauge all the time, and repeated the same run twice about 20 minutes apart with the same results. The WB has been in the truck for 6 months and has not blinked. It may not be dead nuts accurate but has never gone that far off. I trust it. That area of VE is lean. It would be an area that I would ever see during normal driving. Low load high rpm.

Didn't see any KR.

 

I'm just a novice tuner but I have to assume you're in PE mode at this point so what was your A/F ratio? Would the PE multipliers have anything to do with this? Also this is way at the low end of the MAP scale...could it be when you lett off of the throttle...is DFCO disabled? I may be stabbing in the dark but I can e-mail you a copy of my VE table but I'm 1 bar non SD.

Dave