hunting Idle - The eternal Pain in my side

[Ahuremi89]

hey everyone,

i have been tuning cars for over a year now and the results are quite impressive on both S197 and s550 platforms. the cars i tuned and mine included are NA and i'll be tuning my own car once i install my 2.3 roush blower by winter.

as a part of a research i'm doing i removed my Pmas CAI and returned the stock box with a k&N drop in filter and i have still worked on my maf curve. the reason i did this is because summer here is very hot and humid and the open box filter would be a nightmare.

the stock box made the car a bit more stable but there AFR still jumps around from 14 to low 13 up to 15. the car has LTH and 2018 intake and i noticed that the idle last night was not stable at all (Inlet air Temp was almost 170 degrees while parked) and the spark at idle is jumping around from mid 20s up to 33 degrees.

the car was sounded kinda funny as you can feel like it's misfiring although zero misfires on the log or the rpm is playing. i tried to play around with the idle and throttle angle, i zeroed the MAF temp compensation and still it's the same. i even returned the time consistant and delay data to stock ( before they were increased by 25%)

what else is causing this weird idle and what am i missing especially that the car is literally perfect on cruising and WOT.


my mods are Stock CAI box , 2018 intake, Long tube headers. and the car is an automatic 2014 GT.

EDIT:
to explain the issue in a better way, it feels like the idle rpm is acting like its confused, i'll try raising the idle rpm to 800 and see how it works

[Ahuremi89]

ok so a quick update

i decreased the idle spark advance to 5 Degrees instead of 17 on the higher temps

i noticed that the base tune file i used had some changes on spark borderline map 9 which was the commanded map on idle so i returned it to stock.

the car seems to feel better without any maf curve adjustment yet and the temp compensation is off.
maf curve.JPG
my current maf curve.

i think one other factor is the weather it was 103 degrees outside and my inlet air temps were high my average was 120 to 145 degrees with the stock airbox.

what else am i missing or any ideas to help