Please help me tweak my E38 VVE.

[Jayrcr3]

I have a 2011 Camaro SS. It has a cold air intake, a cam, headers and high flow cats installed. I have followed Swingtan's E38 VVE how to, and will post a log that I took yesterday. It seems to be really rich down low, and pretty lean up high when running in the configuration that you use for tuning the VVE. This seems pretty logical based on the mods that have been done. When running on the MAF it seems to be pretty close, around 12.8AFR under WOT conditions. I'm guessing they just tweaked it in using the MAF freq adjustments and never messed with the VVE tables. After taking the log I'm confused on the correct map to use when logging. I have a serial LC-1 WO2 installed. I think where I need help is the map creation in the scan tool. I tried using the E38 BEN map, but when I copied and pasted it it looked nothing like the example in Swingtan's how to. Could someone look at my tune and log and help me get this baby dialed in?

Thanks Guys,
Jay

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[Quickfix]

I have a similar problem. but i think i will command the fuel to 13 afr all around and cancel PE. and then log my serial AFR . i will copy the logged afr table . MAP kpa (column) vs RPM (row) to an excel and then work from there knowing my commanded air fuel is 13 all around.

i was not able to log a map of commanded AFR E38.AFRATIO_DMA (Data) in MAP kpa vs RPM table.

[Chalky]

Why are B8101 and B8102 different? Not sure but shouldn't B8102 maintain default values? It looks like B8102 has gone through a wash cycle and no correction!

The BEN map looks OK.

Someone will step in with E38 experience and get this resolved.

[Jayrcr3]

I don't know why they are different. I must have fat fingered the copy paste portion of Swingtans how-to. The way 8102 looks, is how 8101 looked after I made all the adjustments in the how-to, but before I did the copy paste and generated the new VE and Coefficients on 8101. Ok, I just checked. What ever adjustments you make on 8101 automatically happen on 8102, but Swingtans how-to doesn't say anything about copy and pasting to correct 8102. I'm not sure, but i believe 8102 has no affect on my car. I'll wait for someone else to chime in. I don't know what the Intake Manifold Tuning Valve (IMTV) is, but one table is for the open (8101) and one is for closed (8102).

[Chalky]

Guessing 8102 was adjusted by mistake. I have a tweaked VVE table and B8101 changed by B8102 is as stock. I am clueless as well. Just trying to figure out why the VVE table could be that far out of wack.

One thing I did notice was that your log was really lacking adequate cell hits. Problem was the lower KPA values such as idle & cruise cells had enough hits to verify the VVE table is rich on the low end.

Can you include the stock tune just to see what changes you have been made to the VVE table?

You probably already know that from Aprox. 75 KPA and up, the car will most likely need more fuel air/higher VVE values. Depending on cam, it gets difficult to get VVE table right because 02's are seeing unburnt oxygen and read that as a lean mixture.

[Jayrcr3]

Here is the bone stock tune.

12350

Here is what I ended up with after the email tune. I logged it several times for them, and they adjusted it.

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I should probably just leave it alone, but I am trying to learn this EFI Live and the best way for me to do it is to tinker. :mrgreen:

Camshaft 227/239 .614/.624 115+3

[Chalky]

I am attaching a modified (by me) tune. Load this tune up and do some logging. See if the 75 to 100and KPA values by rpm variances are reduced. Hopefully, they will come down from 15-20% to maybe 1-5%. Regardless, as long as the variances are reduced, you are moving in the right direction. Assuming your logs are good, your tune is really lean at higher rpm.

As far as B8012, it look like GM created that table as part of their tuning package. It is identical to your stock tune B8012 table.

Just a quick look but not much of a mail order tune. :)

I have not done a VVE table. I have done VE tables from LS1/LS6. Same principle just a different process.

I added 15% to your vve tables where it looks lean and did a bit of blending. Also pulled some fuel form your idle area. Run another log and see if the values don't improve. If you can get these values down to a 2% difference, be happy. I have also read articles and some have posted that it may be easier to adjust a few cells at a time versus trying to do the whole VVE table.

Congrats on trying to do your own tune. This is a ton of knowledge on this forum and you have the best software for tuning GM products.

One final thing, did you remove the MAF lead from your MAF connection? :)

[Jayrcr3]

Thanks for the help. I really appreciate it. I did not remove the yellow wire. I thought I read somewhere where it may not be necessary. I could be wrong though. I can pull it and do another log if I have to. I was kinda under the impression that setting the C0301 to C0303 and C0305 disabled the ECM from using the MAF.

[Chalky]

I don't know for sure but there seems to be a greater emphasis on disabling the MAF now than in the past. From my understanding, the MAF can still influence readings even with tables disabled.

[swingtan]

Guys, the 2011 Comaro doe not use an inlet manifold tuning valve, note that {B8026} is set to "NO".

This means that {B8102} is not actually used at all and can have any shape at all. Only {B8101} will be used in a normally aspirated car.

If you are throwing a P0101, P0102, P0103 code, then the MAf will not be used at all. Those codes tell the eCM that the MAF signal is bad and should not be used.

Simon

[Chalky]

So if no code, MAF has to be disabled by pulling power? I thought your tutorial stressed disabling MAF by pulling yellow wire>

[Jayrcr3]

Thanks for the info Swingtan. I will eventually mess with it enough I'll figure it out. I have learned quit a bit just messing with it in the last week or so. I'll load chalkys tweaks tomorrow, and see what happens. Thanks again for helping me guys.

[swingtan]

Chalky: The yellow wire is the signal wire. Pulling it will certainly bring up the code ( unless the codes have been turned off instead of being set to "non emissions" ).

Jayrcr3: If I get a chance latter I'll look at both your tune and log, I've been a bit busy for the past 3 months.....

[Jayrcr3]

I will check, but in the tutorial he also has you disable 3 MIL settings. I'm guessing they are for the three he just mentioned, so I will have to re enable those MIL settings to verify those codes are being set.

[swingtan]

The tutorial does not say to "disable" the codes. There are two steps involved and quite a few only do half the job, causing problems.

Under "Engine Diagnostics" there are two area's to make adjustments...

DTC Type: Under here the codes are to be set to "Non Emissions". If you set these to "Disabled" or "Not Reported" then the ECM will still default to using the MAF, even if the MAF has been removed from the car. If the MAF is removed, the car will start but die instantly.
DTC MIL: Under here, the codes are set to "No MIL". This prevents the dash DTC lamp from lighting when the ECM fails the MAF codes.


Get these wrong and tuning the VVE will be very difficult.

Simon.

[Jayrcr3]

I don't believe there is anything in the tutorial about changing anything to non emissions. I will check again tonight when I get home. This may be something I missed.

[swingtan]

Actually, there isn't, you only need to set "Non-Emissions" if you are going to leave the car in MAFless / SD mode. If you are going to swap back to using the MAF, then only the "No-MIL" setting is required to stop the dash lamp.

[Jayrcr3]

The tutorial does not say to "disable" the codes. There are two steps involved and quite a few only do half the job, causing problems.

Under "Engine Diagnostics" there are two area's to make adjustments...

DTC Type: Under here the codes are to be set to "Non Emissions". If you set these to "Disabled" or "Not Reported" then the ECM will still default to using the MAF, even if the MAF has been removed from the car. If the MAF is removed, the car will start but die instantly.
DTC MIL: Under here, the codes are set to "No MIL". This prevents the dash DTC lamp from lighting when the ECM fails the MAF codes.


Get these wrong and tuning the VVE will be very difficult.

Simon.

I believe you have found the problem. Mine were set to "B: 2 Trips, Emissions Related" I changed them to "Non Emissions". I will get another log and see if it comes out better.

[Jayrcr3]

Ok guys, I think I'm finally getting somewhere. I threw out all my previous logs and tunes and started back at square one. I have made 2 adjustments to the VVE, but I havent logged the second adjustment yet. Here is my before and after. the AFR's are much closer in the second one. I think I might be heading in the right direction.

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[Chalky]

Definitely going in the right direction. Big improvement between 1st and 2nd pass.