Strange lean spot @2500 h/c ls7

[arsautorepair1]

So I've been running maf only for last few years, finally tackle my ve table on 2006 ls7 h/c/I. Just got the new aem wideb and that communicates through the can, really sweet! Any way I get a strange lean spot right at 2500rpm in the first 3 gears at low throttle, car just falls on it face. Only at 2500 rpms. I logged the eq error then copied it over to the vve, now I have a huge fueling spike at 2500rpm and it won't go away. Any idea's?



vewidebandlog2.hpl
openlooptuningafrve.hpt

[schpenxel]

I would switch to the 2 bar SD OS and use that so you can get a regular VE table instead of dealing with VVE

I would also put it back in closed loop and tune part throttle with fuel trims instead of with the WB

It's also not going into PE until you're quite heavy on the throttle or at high RPM's--I'd change that a bit but that's just me and not really related to your question

Add VE airflow and Dynamic airflow to your logs

Any chance of an exhaust leak? Those WB readings are all over the place..

The 2400 RPM row of the VVE table is a lot lower than the 2600 row.. it'a almost the same as the 2200 row. Raise it up, see if that gets rid of the weird lean'ness

I'd still go back to closed loop though.

[arsautorepair1]

I would switch to the 2 bar SD OS and use that so you can get a regular VE table instead of dealing with VVE

I would also put it back in closed loop and tune part throttle with fuel trims instead of with the WB

It's also not going into PE until you're quite heavy on the throttle or at high RPM's--I'd change that a bit but that's just me and not really related to your question

Add VE airflow and Dynamic airflow to your logs

Any chance of an exhaust leak? Those WB readings are all over the place..

Thanks for the help, first time tackling the vve I logged the 02 errors twice to get it some where close in the ball park. It was +20 and -20 all over the place. Had the lean spot at 2500 rpms then too. Then did two logs with in it open loop with the wideband, still had the lean spot at 2500 rpm. I'll switch it to the 2 bar os tomorrow and try again adding the pids, thanks for the help. It surprisingly runs really smooth in sd even with the fueling everywhere. Doubt there is exhaust leak, I investigate that too

[schpenxel]

Keep in mind the VE tables will start out blank when you do the upgrade. Thinking about it some more it might not be worth the effort. Also, MAP sensor values will automatically change and need to be changed back if you do the upgrade. Those are common issues that pop up all the time here.

I'd throw it in closed loop and see how it does after smoothing out the gap between 2200 and 2600

[arsautorepair1]

So I switched back over to MAF only and the lean sports @1750 and @2500 disappeared.
happyvalleymafopen.hpl

Returned VVE with fuel trims and there back
dblmtnve.hpl

This is VVE open loop, even worst. Always exactly @2500 huge lean spot can really feel it. It's only on SD or VE only. What could cause this?
happyvalleyveopen.hpl

[schpenxel]

Post current tune

In the original one you posted the 2400 RPM column of the VVE table is actually lower than the 2200, 2000 and some of even the 1600 RPM's rows. The 2600 RPM row jumps way up then 2800 goes back down

Overall, very unsmooth, so that would be my first guess, but without a current tune it's a stab in the dark.

Post current tune though, I'd be curious to look at it.

[arsautorepair1]

Post current tune

In the original one you posted the 2400 RPM column of the VVE table is actually lower than the 2200, 2000 and some of even the 1600 RPM's rows. The 2600 RPM row jumps way up then 2800 goes back down

Overall, very unsmooth, so that would be my first guess, but without a current tune it's a stab in the dark.

Post current tune though, I'd be curious to look at it.

Basically I create a VVE table, log the error and copy, past multiple over the table and hit calculate coefficients tab. Then re drive and I have the massive lean spot right at 2500rpm, take the error log and copy and paste over and hit calculate coefficients and it gets even leaning, even though I'm adding fuel. That's why I have that massive spike on my vve table. Maybe I'm doing something wrong copying and pasting and hitting the coefficient table, I'm new to the vve tuning.

When I first create the table the car runs pretty smooth even though it's 10-15% rich in the lower kpa area's and 5-8% lean in the higher load area's. Then soon as I do one vve edit the massive lean spots show up @2500 and sometimes @1750. Switch it over to a maf tune and it runs fine, maybe I'll just leave it maf only cuz it runs pretty well like that.

[5FDP]

It's best to use the speical paste multiply by half so the changes aren't so huge and use the editor functions to your advantage. You have the ability to smooth the tables and correct for any minor dips and bumps in the curve.

[schpenxel]

Yeah, I'd at least smooth the whole thing a few times. You have some pretty large peaks/valley's which I bet is not helping this issue. Look at the graph view.. it should be relatively smooth, not suddenly going up and down

Copy/paste special is a good starting point but you have to apply some common sense to it too.. otherwise you end up with some cells totally untouched and some that get significant changes, which just isn't right. You should apply trends that you see to cells you don't hit also.

Whether that's the issue or not, I don't really know. It seems like a good place to start though.

[wetcoast]

Be careful about where your zones are in your VVE tables. The BlueCat tool used to move them automatically to ensure a smooth VE table. HPT doesn't and you have to move them manually.

*edit*

Here's why:

Screenshot 2016-08-11 09.28.57.png

[schpenxel]

Looks good to me

[5FDP]

[arsautorepair1]

Ok I started over for the third time from scratch, used the multiply by half this time. Did three logs and edits and the vve table looks much better. Dunno if I had a slip of the finger or the multiply functions screwed me up somewhere. Thanks for help.. Here is the ve table nowfinaltune.hpt

[schpenxel]

Much smoother!

[wetcoast]

Ok I started over for the third time from scratch, used the multiply by half this time. Did three logs and edits and the vve table looks much better. Dunno if I had a slip of the finger or the multiply functions screwed me up somewhere. Thanks for help.. Here is the ve table nowfinaltune.hpt

Getting there but there's still some work to do. Try moving the zones around where the sharp edges are on that VVE graph to see if you can smooth it out more.