AutoVE - Lean issue

[brianjw4]

I'm trying to do an SD tune and am having a strange issue. The idle is somewhat high but steady - about 1,000 RPM. When I hit the gas pedal the engine goes lean, so lean that it stumbles. It does this when it's cold or hot, doesn't seem to matter.

This is a 5.3l and I've added 60lb injectors as this is a turbo build. I am planning to use the COS3 ultimately, but wanted to get the basic drivability setup first before installing it.

Any help would be appreciated.

This is the log and the tune file I'm using:

[joecar]

Hi Brian,

You have CL enabled via B4205... to disable CL set this table to 284°F.

Looks like you might have a manifold airleak, MAP occasionally jumps up.

Wideband AFR doesn't look right at all.

What mods...?

If you have a FlashScan V2, then you will get better wideband data by using the serial connection.

[joecar]

Also, I don't see a DTC for the MAF, so the PCM is still reading the MAF... set P0101,2,3 in C6001 to Non-Emissions... and check that one of those gets triggered.

[joecar]

You might want to check for:
- injector leaks.
- intake manifold leaks.

[brianjw4]

Thanks for the reply. I'll disable the CL to start. The motor is basically all stock with the exception of the injectors (60lb siemens) and changed the original truck manifold to stock LS1. I have a complete turbo system in place, although I haven't connected the charge pipes yet so it's still running naturally aspirated.

Not sure what could be wrong with the wideband reading. It's an NGK and I have the calc_pid file setup correctly, I think. Here is that file

[brianjw4]

Ah more good info - I thought "not reported" would disable the MAF. I've made the changes and am going to flash again and see if there are any improvements

[joecar]

That calc pid looks right.

I looked at the V2 options, looks like V2 doesn't do serial AFR for the NGK.

Your NGK AFR is flat pegging at 15.685... looks strange.

[joecar]

Ah more good info - I thought "not reported" would disable the MAF. I've made the changes and am going to flash again and see if there are any improvements

Ok, post your results.

The PCM has to see a MAF DTC in order to failover to the VE table.

[brianjw4]

That certainly made a difference! The car is actually driveable now, thank you! Still getting a lean condition when I come to a stop and go again.... I don't have the VSS hooked up so that may be contributing to that problem, not sure.

Here's the log: