Cammed LS3 maintains revs around 2.5k when shifting/clutch in or while in gear.

[c4z]

Hey guys, trying to figure out why revs won't drop below 2.5k while I'm driving, or when shifting while driving. Car will idle normally, I can rev at Idle and RPMs drop normally. However, if I drive the car and I'm downshifting for a turn, the engine will maintain or increase revs to ~2.5 if the engine is below that point. If I slow down while in gear below 2.5k and take my foot off the gas, the engine will again increase revs and not slow down below the ~2.5k point.

Any insight into why the engine would do this? Attaching tune and log file.
2010 LS3 2SS TXSSpd stg2cam swg_base 2c4 v3.hptLog for Tune 2__casey v4.hpl

[5FDP]

Those fuel trims want me to think vacuum leak, they start to peg out at +25-30 even at idle.

[c4z]

I will certainly double check that, but we are still in early stages of tuning for the new cam. I'm currently tuning the MAF at the moment to bring the ST's in check. Maybe this is part of the issue.

When the car starts and I don't drive, just rev at idle it acts normal. No weird revving, idles down normally. It only does this when immediately when I start driving, or if I rev in neutral after driving it will just rev up. Still seems odd for a vacuum leak.

[lukearmstrong1990]

if you don't have a vacuum leak or a big hole drilled in the TB blade then you're well lean 3000hz and below and need to use that MAF table to add some fuel. your have dynamic rpm disable set at 100rpm meaning its using MAF full time. the re-enable rpm is 0 so it'll never go back to VVE calculations.

remove some idle airflow 1600rpm and up. like start back with factory numbers 1600rpm-8000rpm

remove some timing from your coastdown and base idle spark tables above 1000rpm from 0.24-0.00.

or just cheat and enble adaptive idle from 500kmh. that will maintain your target idle anytime youre coasting. that is masking your problem, not fixing it and adaptive idle will disable while the clutch is depressed.

to me it seems you have far far too much air. be it from an airbleed or vacuum leak you need to investigate. being lean will also help rev hang on coast.

[c4z]

Thanks! I will check it out. I agree the MAF is far too lean in the low HZ range.