08 c6z rpm bounce help?

[ajxtreeme]

My 08 c6z idle doesn't seem to cooperate when messing with the idle tables. Sitting in neutral not moving, I blip the throttle to around 2-3k rpm and on its way down it'll hit the target idle but then bounce up and down between 900-1300 rpm. Car has Heads, TSP stage 4 cam, arh 2' catless, NW 102 mm, Ported MSD, e85 flex. If I blip it under 2k the bounce isn't as severe, anything past 2k and the rpm will bounce up to 1300 after hitting its target idle. Car didn't have this issue when I was on my stock ecm, it was MAF only at the time but when I would blip it the rpm would drop down and catch perfectly to the target idle. no bounce. The only difference this time is that I went with Dave Steck's 2010 ecm upgrade from DSX Tuning. Can't get it to catch perfectly with this new ecm, any ideas? Attached are the 4 tune files, 2 from the stock ecm and 2 with the new ecm. Jesse Red C6Z Stock ECM MAF only TUNED.hptJesse Stock ECM and 102mm Throttle Body LOG.hplJesse New ECM TUNED 20deg idle still hanging.hptNew ECM TUNED still hanging.hpl

[lukearmstrong1990]

I would try

setting DFCO enable RPM 1650
disable RPM 1350

set DFCO entry and exit spark tables to 10* below 3000RPM

set your adaptive idle spark corrections for "underspeed" to the identical values populating the overspeed resprective tables only make them a positive number. currently after 200RPM underspeed spark correction stops.

add some base final airflow 800RPM and below to help catch return to idle.

increase the numbers in the positive section of the RPM axis in the idle integral airflow table