Infamous Hanging Idle issue

[00ws6bmoore1488]

Ok I took my car to a local tuner who is new in town to be dyno tuned and he tunes with hp tuners. The car made great numbers on the dyno but the low end street manners are terrible. I have recently bought hp pro and am very new to tuning. I have also bought the tuning school Level 1 GM books but for the life of me, i cannot get rid of the hanging Idle. If I come rolling up to a stop sign or red light and push the clutch in the rpms jump to about 2000 and take at least 10 seconds to calm down back to my commanded Idle. I'm at a loss, Ive tried Throttle cracker, throttle follower, Base airflow and the list goes on. The car runs like a champ up top and AFRs are spot on but the bottom end manners are terrible, when it does finally Idle down, sometimes it stalls. The tune I attached is his tune, only thing I touched on it was disabling skip shift, bc I installed a tick performance stage 5 T56 Magnum and it kept throwing codes for skip shift. The car is a 00 WS6 M6, p&p heads, tsunami V2 cam, FAST 102 intake, FAST 102mm TB, Lingenfelter 100mm MAF, kooks headers and true duals. I have also had the car smoke tested and do not have any vacuum leaks. The only thing I can see from data seems to be the commanded IAC seems to be falling extremely slow when the Idle is hanging and I have no Idea how to fix it. Im lost any help and advice would be greatly appreciated

2000 WS6 Kyle Tune Skip shift disable.hpt

[5FDP]

Having not done a setup this "extreme" or with this many mods I can't say the exact causes.

But a few things to note, with all those mods done. This tuner hardly even touch the VE table at all, it's just about as stock as can be with minimal changes in the lower rpm/map pressure area. That MAF curve looks pretty bad, it's not smooth. It's got a little dribble to it, then a large hump in the high rpm range.

Are you still on stock injectors? Those little guys must be screaming for life with how much airflow this car can handle.

I know there is a idle tuning layout around here somewhere, russ k has posted it before. It helps a lot with getting the idle dialed in but you have other airflow tables that need a lot of work too and could very well be making this problem even worse.


It's easy to dyno tune for full throttle, smacking it with a lot of fuel and timing is easy. It's actually tuning the rest is the tough part. I'd ask for your money back. Commanding 11.7 AFR with mid to upper 20's for timing sure does leave a lot of power on the table. You could be upwards of 12.5 afr with good timing and should make more power. Needs injectors though, in my eyes.

[00ws6bmoore1488]

Thats what I was afraid of. Yes he said the injectors hit 120% on the dyno so I ordered 42# injectors, just havent gotten them in yet. It put 452hp down on the dyno so I just assumed he knew what he was doing. He is the only tuner in a 300 mile radius so i'm sort of screwed and I don't know enough about this yet to do it on my own. I just honestly hate driving the car with the hanging Idle its killing me.

[SultanHassanMasTuning]

i have tuned this cam before, you need at least ls2 injectors as minimum. also i would never maf tune this combo2000 WS6 Kyle Tune Skip shift disable_test.hpt

[Ely907]

I watched a video where a guy pulled spark in the few areas where the idle was hanging maybe that will help

[00ws6bmoore1488]

The 42#s should be plenty right?

[SultanHassanMasTuning]

swap in LS3 injectors with their adapter clips and it will be good for ovr 500 hp

[dermotw]

Hmm well that idle base airflow is way more than mine for a start, my mods are in the sig, plus your MAF curve looks nothing like right, with that hump in it... VE table just looks standard, more or less.. Apparently you still have the EGR and the COTS on in that .hpt file? Is that so??
I run 36lb injectors and it's enough for mine anyway... Almost every one of your throttle follower values is about double mine.. Mind you, mine is a 376 don't forget...

kr D.

EDIT: Oops sorry forgot, if your IAC is shutting then the throttle is just too far open at idle, wind the stop back a turn (or 2). It can't control idle if it's wound down! Unfortunately that will mess up the rest of the idle settings somewhat.. BTW your IAC reset position is at 310, usually it's 160, dunno if that matters 'cause I've never changed it.

[MMGT1]

To me it has high timing and low RAF. Change timing to 19* @ Idle(Blend that into your High and Low tables). Run RusK's idle config and you should end up closer to 13g/sec RAF at operating temp. You also will not have air values that are unchanged from 60*C to 140*. From 110* to end sure...but before 110* it should ramp toward desired air at full temp. I find idle is much more stable when you get timing down and use air to your advantage. Coming to a stop it's already aiming for a good amount at 13 the stability is just better to me.

[00ws6bmoore1488]

OK I did the Russ k idle config this morning and changed timing and it made a world of difference. it's almost perfect now. gonna do a little more tweaking on the throttle Follower and throttle cracker and I'm pretty sure it will be g2g. Thanks so much for all the help guys. one more question, when I put the new injectors in will it require a completely new tune?

[5FDP]

Yes.

That VE tune needs a ton of work for the mods you have done and that MAF curve still looks bad.

You'll be tuning both of those before you go into tuning timing and WOT fueling.

Fixing the idle is great but the rest of tune is still very much a work in progress.

[Area47]

throttle follow > decay and delay p/n and gear. airflow. tweak the cracker tables a smidge as well. im fighting a similar thing and made some headway on a funky ass setup t/a

[00ws6bmoore1488]

Hmm well that idle base airflow is way more than mine for a start, my mods are in the sig, plus your MAF curve looks nothing like right, with that hump in it... VE table just looks standard, more or less.. Apparently you still have the EGR and the COTS on in that .hpt file? Is that so??
I run 36lb injectors and it's enough for mine anyway... Almost every one of your throttle follower values is about double mine.. Mind you, mine is a 376 don't forget...

kr D.

EDIT: Oops sorry forgot, if your IAC is shutting then the throttle is just too far open at idle, wind the stop back a turn (or 2). It can't control idle if it's wound down! Unfortunately that will mess up the rest of the idle settings somewhat.. BTW your IAC reset position is at 310, usually it's 160, dunno if that matters 'cause I've never changed it.

I have no egr on the car anymore and I'm not sure what COTS is, could you point me in the right direction?

[00ws6bmoore1488]

Nevermind I found it, thanks for the heads up, sorry for all the dumb questions