Commanded AFR goes lean at high MAP value

[wadesns]

I have been working on my VE table daily for about a week now and it seems as if the closer I get the worse my truck runs under a load at low rpms. So my truck has a 384ci with fairly large cam and port/polish heads. Also running a T-56 with a 4.56 gear and 30" tire. I am attaching a log file and a bin. Log file is short just a simple take off nothing fancy I ran through 5 gears and near the end of the log you can see the commanded afr go lean. I know that my afr is off a bit because the previous tune had 1.5* more timing in the trouble areas. I thought that it may be that my timing was too high. Also if I give it to much throttle it will detinate Anyways any help would but greatly appreciated.

Thanks,
..RJ..

[5.7ute]

What wideband are you using?

[joecar]

Hi RJ,

Open your log and tun files simultaneously (and enable pid linking in the tunetool):

In the scantool, position the cursor at AFR 16.5 (you will see MAP >= 80 kPa);

In the tunetool, look at B3605:
for MAP at/above 80 kPa this table is set to EQ 0.885 (AFR 16.5) between 176F and 212F... this is what your log shows being commanded.

You need to set your B3605 to some reasonable/richer values in those areas.

Your B3605 is not suitable at all... you're not really saving fuel, more likely you're stressing/damaging the motor.

[wadesns]

NTK AFX from NGK

[joecar]

Also, something is wrong with your MAP sensor, DTC P0106 "MAP sensor performance" is present... you need to fix this before you can do any tuning.

Also, your VE table looks wrong.

Also, I take it you have removed the MAF sensor...?

[5.7ute]

No wonder you are detonating. you are commanding a leaner mixture as load increases.(map value goes higher) Are you viewing the commanded fuel tables in Lambda ? This is the reverse of EQ & can cause what is happening in your tune.
Go to edit/properties/display and make sure you are viewing the commanded fuel tables in AFR. Close then reopen the tune file for this to take effect.
Then richen up the high load areas in the B3605 commanded fuel table from 60 kpa to 100kpa. Have an AFR around 12.7 to 1 in the 90 to 100 kpa area & blend down to 14.63 in the 50kpa area.
Damn, too slow.

[joecar]

lol... hi Mick...

[joecar]

I see the calc pids NGKF and NGK2...

NGKF must be a typo... maybe it should be NGK1... I let Paul know.

[5.7ute]

I will have to take typing lessons.

[wadesns]

joecar I have tried to "enable pid linking and cant seem to find what you are talking about. I tried the "automatically track linked scan tool cell(ctrl+K) and that doesnt seem to work either. Is this cell outside of what the auto ve tutorial recomends to change in the B3605 table?

Thanks for your help
..RJ..