sierra 2008, AFR doesn't stay constant @ wot

[odd boy]

Hi everybody,

I tuned sierra 5.3L 2008, whenever I got the AFR @ WOT 12.8 by tweaking the PE, it doesn't stay constant after it shifts to the next gear 2, then 3rd. I got this 12.8 in the first one. Any idea??

It goes to 11.7 .... 10.8

[odd boy]

Any help gents!!

[mr.prick]

What are your mods?
It could be a few things, VE table needs adjustment,
injectors going "static", TP% variance ect.

[odd boy]

What are your mods?
It could be a few things, VE table needs adjustment,
injectors going "static", TP% variance ect.

what do u mean by "your mode"?

[joecar]

He means "what are the modifications on this vehicle?".

[odd boy]

ram-air and cat-back

[joecar]

Hi everybody,

I tuned sierra 5.3L 2008, whenever I got the AFR @ WOT 12.8 by tweaking the PE, it doesn't stay constant after it shifts to the next gear 2, then 3rd. I got this 12.8 in the first one. Any idea??

It goes to 11.7 .... 10.8

I've seen this before, but I do not know the exact reason... the load is changing but the tables are not accounting for it...

Post log/tune files.

[Stealth97]

I've seen this before, but I do not know the exact reason... the load is changing but the tables are not accounting for it...

Post log/tune files.

Ditto. I have heard of this happening on other ECM's (Non GM, like aftermarket AEM for example), where the AFR is only constant in one gear. I would like more information and I watch this thread everyday.

A new aftermarket PCM called the ProEFI (made by the famous Jason Siebels of AEM fame), might have the capability to tune based on gear, AND I believe he is using a Bosch or Motorola late model style PCM (similar if not the same as GM uses stock).

I need to do more research into this ProEFI thing and see exactly which controller it is and how we can utilize it one day (maybe for circle track racing?)

Eric

[odd boy]

here is the file

[GAMEOVER]

On my 2008 Silverado, I had the same problem, At WOT my AFR kept going below the command fuel setting's I had adjusted in table [B3618]. With the wideband fitted, and messing around with quite a few adjustments. On my truck(tune), the COT [B0804] was causing the overly rich condition. When I disabled it command fuel was right on,(using WBO2) when I re-enabled it, overly rich!!! So instead of disabling COT[B0804] I adjusted table [B0805] to match command fuel at WOT (richest setting in my tune) it's been working perfectly...