Timing/O2 Fluctuation Procharged LS2 GTO

[Hooch]

Working on a E40 GTO with a P-1SC Procharger. Car was previously tuned and drives/runs fine and AFR is running where it should be. However, when I started data logging the timing and O2 voltages are oscillating significantly. Reducing the injector PW helped some but car is still having oscillation issue. Any suggestions on what else could be causing this issue?

2005 GTO_Procharged_14_08.hpl

[07GTS]

thats normal for CL operation the 02's cycle like that from the fuel trims control, spark is just correcting to control idle could be a bit choppy looks like idle airflow is a little high and its removing timing to bring it down a smidge, some like a idle like that or it could prob be cleaned up so its smoother but will take some work

[smokeshow]

You have no idle control with the throttle. This is what I call a 'trampoline tune'...final min airflow is set too high and clips the throttle authority to remove airflow for idle, so the throttle remains motionless at idle. It sits on that minimum airflow, bouncing with the spark oscillation. Some people are okay with that, but it's a sloppy way to get a DBW vehicle to idle and causes driveability issues. You'll need to bring the min airflow down to return control to the throttle. But it looks like the MAF and/or VVE will need some work too. Cylinder airmass is unusually low...adjusting the min airflow will likely reveal problems in the MAF/VVE cal that are currently hidden.

[Hooch]

You have no idle control with the throttle. This is what I call a 'trampoline tune'...final min airflow is set too high and clips the throttle authority to remove airflow for idle, so the throttle remains motionless at idle. It sits on that minimum airflow, bouncing with the spark oscillation. Some people are okay with that, but it's a sloppy way to get a DBW vehicle to idle and causes driveability issues. You'll need to bring the min airflow down to return control to the throttle. But it looks like the MAF and/or VVE will need some work too. Cylinder airmass is unusually low...adjusting the min airflow will likely reveal problems in the MAF/VVE cal that are currently hidden.

Thank you for the advice, smokeshow. I recalibrated the MAF and will look at messing with the min airflow. I also just realized the injector data doesn't look correct, so that will need adjusting as well.