5.7 cammed idle good one day, terrible next. What's changing?

[S-351R]

Been a saga with a '21 5.7 with a healthy cam that needed a lot to get it to idle from the beginning. Fueling and spark, and typical changes did not work.

Reduced TB airflow tables to give more air/TPS and that seemed to fix it very well under all conditions and revving. Later, it developed a throttle hang on free rev and a little bit of cruise control effect.

Worked the TB airflow data back, eventually to stock, and idle surprisingly stayed great. Then overnight, idle is back to immediate stalling and undriveable.

Repeated the entire process again, again back to stock.

Latest is that even with stock TB data, again developed a 4k rpm rev hang off of a throttle blip, and a little cruise control effect in 1st/2nd. Did a TB Relearn process and the rev hang/cruise immediately went away, but idle was back to being crappy. Changing issues have all been with consistent Engine and Air temps, so doubt that it's tied to a temperature setting.




*So a key question is what aspects of the Dodge system can change or evolve like this?

- PCV system, intermittent Vacuum Leaks (not sure how..), Idle Adaptives that reset, ...??

Latest tune file and some evidence of stalling in attached log.

Any thoughts appreciated!

[james1595]

Dodge vehicles have adaptive learning, meaning it will learn over time different aspects. So what works today, may not work tomorrow. It can be very annoying, but nothing to difficult. What all is done. I see in the file name its got a whipple, and obviously a cam. Anything else?

[S-351R]

Ok gtg on the adaptive idle, just surprised that it can be so different so quickly. Does adaptive reset with any loss of PCM power? Car has a kill switch but ?think? it only cut?s positive to ignition.

Whipple -1 sized pulley, stg 2/3 sized choppy cam, stock TB, hellcat injectors. So nothing particularly unique, just a seemingly sensitive buggy car?

[f.creek-ranch]

After do the changes reset all adaptives and log from startup.

You can disable TB adaptive, this will work for me to dial it all in,

[james1595]

my dads car had a similar issue, its cammed, and a manual, but it would act like it had cruise control and the rpms would fluctuate when driving with the clutch pushed in. also mine had an issue that was like yours, one day it would be good, the next not so good. i adjusted a few tables that helped us both, so you are free to look at it. also it seems to have taken about 10 seconds to restart? seems like a start up issue as well. might need to rework your fueling, because it seems to be dumping a ton of fuel when you let go of the gas. but us not being supercharged and not having alot of knowledge with it, i didnt want to touch the fueling or airflow tables. is anyone tuning it, or just you?
2021 Charger Whipple Cam Pulley idle-decel changes.hpt

[edcmat-l1]

Post your original unmodified tune file. That way I can see what you've done. Chances are it's just not dialed in correctly.