Fuel Trims/Learning will not disable

[Meister]

Working on a 2002 LS2 based Corvette
GENIII LS PCM

I have forced it into OL, turned off all the STFT and LTFT stuff and it still wants to make STFT corrections. When I use the DVT to force into OL and disable learning it works for a bit then starts learning and making corrections all over again..

[SSpdDmon]

Tune file?

[Meister]

How do I attach a file here?

[ScarabEpic22]

At the bottom where it says Post Quick Reply and Go Advanced, click Go Advanced. Type your post, then scroll down to Additional Options. There will be a button labeled Manage Attachments, click it then Add Files in the upper Right. Click Select Files, select the ones you want, then click OK then Upload Files. Click Done then you'll be back at the main posting page, click Submit. Should be set!

(Sorry if its a little wordy)

[joecar]

Is B4206 disabled...?

[Meister]

Here is the latest working calibration. Another annoying issue I am having with the maf failed is on startup, the maf does not "fail" right away and the car runs like crap. Once it fails (I can see it when my CEL comes on) it purrs like a kitten

With the cam in the car I do not want any fuel correction right now (or ever at idle)....especially when tuning. Once it is done, I do not mind having some adjustment during cruise

10519

[Meister]

Is B4206 disabled...?

Does not exist

[joecar]

Hi Paul,

COS's have B3647 instead of B3605 and B4206...

for any cell in B3647 set to stoich AFR, the PCM will trim using STFT.

this is a feature (SOL = semi open loop);

[Meister]

COS has B3647 instead of B3605 and B4206...

for any cell in B3647 set to stoich AFR, the PCM will trim using STFT.

This is already set and done. I do not want any trims at idle. Cam is too big thus resulting in a false lean condition at idle and its all over the place. I use the DVT to kill fuel trims and force back into OL but it only lasts for a few minutes

I need to kill all learning/trims and keep it in OL.

[joecar]

All those lambda 1.00 cells will trim using STFT.

[joecar]

i.e. I'm saying you have to set those cells to Lambda 0.99 or 1.01 to avoid SOL/STFT.

[Meister]

All those lambda 1.00 cells will trim using STFT.

This is a commanded AFR table. I am wanting it at 1 right now while tuning and with all STFT and LTFT off it should not correct. My VE should be adjusted to get it to 1

[joecar]

That is what I am saying... the COS will trim on B3647 cells that are 1.00.

If the COS hits a cell in B3647 that is 1.00, the COS will trim to 1.00 using STFT.

This is a feature of the COS's.

[joecar]

If you set it to command 0.99 lambda, and your wideband measures 0.99 lambda, the BEN will be 1.00 and VE is good.

i.e. you should be adjusting the VE to make BEN converge on 1.00 regardless of what is being commanded.

[joecar]

If you notice, the COS does not have B4206 (enable/disable STFT on 1.00 cells in OL table)...

the OL table cell value being 1.00 enables STFT trimming on it.

[Meister]

Ok, so if I set this to .99 or something else other than 1.0 it will disable trimming?

[joecar]

Ok, so if I set this to .99 or something else other than 1.0 it will disable trimming?Yes, that is correct.

[Meister]

Interesting and exactly what I want. Trim off idle and cruise, no trims at idle and wot. Fantastic

Now, if I could only figure out why when I first start the car the maf is not failed (CEL is OFF), it runs poorly for a few seconds until CEL kicks on (indicating maf is failed)....the maf wire is removed from the harness

[joecar]

Does C6001 have the MAF DTC's set to 1-Trip...?

[Meister]

Does C6001 have the MAF DTC's set to 1-Trip...?

Yes these were set properly along with 101, 102, and 103 to tell me the MAF has been failed (which I turn off to deliver the car).....9 out of 10 times it happens where the CEL would not come on, it would run poorly and then once the CEL comes on it would be perfect. That 1 time, which I cannot attribute to any condition, it is perfect