94_LT1_TransAm

I have a tune and the car runs fantastic while driving down the road and taking off from a stop. The only thing I've noticed is the idle. When started and either at a stop or in park/neutral, the idle kinda surges slightly but not much. I only noticed it when looking at my datalog software that the idle settles down near 675-700 but spikes up towards 775-800 every now and then. Also, I barely have any lope at all, due to this. Does the idle need to be lowered? Any suggestions? Thanks

SS RRR

iTrader: (2)

Aftermarket TB?

94_LT1_TransAm

No, everything is stock besides cam components, ls1 lid, and headers

fbody_brian

What's your timing at idle?
Does it do it both closed and open loop?
It seems like your idle rpm is in a good area, I have a little smaller cam and that's where my idle is set.

94_LT1_TransAm

according to eehack, it says 33 degrees advanced i believe
yes on both loops

steveo_

what are your IAC steps during hot idle?

also graph timing advance vs iac steps vs rpm to get an idea of why the fluctuation is happening... lt1 uses timing advance for fast idle corrections, sometimes you have to mess around with that to get it right.

you can try lowering timing advance with eehack (or raising it) and playing with idle targets till you find a happy idle