Hey guys, wondering if anyone has seen this issue. Im tuning an 09 Canyon with a turbo, when I make the 2-1 downshift it goes crazy lean but when it shifts into 2nd gear its fine. The fuel pressure stays up and doesn't drop off. It does this on both 93 octane and E60 thats currently in it. Ive attached the tune and log with AFR data, if anyone has any ideas Id love to hear them. Ive tried adding airflow gain in openloop, adding to the impact factor with no change.
Last edited by BLKHAWK; 03-19-2022 at 11:53 AM.
I think it's spark timing related. Torque management drops spark down to ~2* and it probably misfires a bit, and the unused oxygen is being detected as a lean condition.
Fueling also needs more work - WB is reading stoich but only because it's in closed loop and trims are removing ~10%. It would read rich on the WB if you made no changes other than forcing it open loop.
I understand that, Im trying to fix the downshift issue. I assure you its lean on the downshift, downshift TM makes the timing drop down but it falls on its face when it goes lean. look at the inj pulse width in 1st vs second gear the ecu is clearly pulling fuel. that is the issue im trying to fix. In fact if someone wants to take a crack at fixing the issue with the tune posted above Ill paypal that person $300 if it fixes our problem.
at 4200 RPM in ist its 144 kpa and 16.0 AFR in second gear its 149 kpa and 11.2 AFR
Last edited by BLKHAWK; 03-19-2022 at 11:50 AM.
Read out the trans tune, disable downshift TM and then dial in the shift times and pressures. Looks like you might have most of the upshift TM's disabled just looking on the engine side just not sure about the trans side since you didn't post it.
2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80
~Greg Huggins~
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Ive tried disabling downshift TM with no change, If youd like I can email you the complete file ecm/tcm. If the changes you make fix the issue Ill send payment
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