Idle dip coming to a stop, saw tooth timing, please help

[Maxspeed96ct]

g8 with a mild cam and lsa blower. I had the cam prior. id1050x injectors with data from dave steck. Although the injectors have been removed and reinstalled in a new rail? hopefully one of them is not failing or dirty?

as you can see in the logs, when I come to a stop the idle dips about 100 rpm below commanded, and the timing is like a saw tooth.

Ive gone back and fourth with the fuel trims, ive tried to really crank up the throttle follower and the case airflow and it helped slightly but really just wanted to push through the breaks.

Right now it seems best with the base airflow high but the follower just slightly lower then stock ?

I feel like its a timing issue but cant figure out why. over and under spark tables are stock, I did try to make them slightly less aggressive but it made no difference

what else would cause this? Ive tripled check for vacuum leaks, my only other thought is my brake booster line is 3/8 while the oem one is 1/2 but I don't think that should effect it like this ?

[Maxspeed96ct]

End of the log shows it best

[adunphy]

I suspect Torque Management is at work. As a test, try setting your

Spark -> Advance -> Spark Limiters ->Spark ramp out ->Spark Minimum TqMgt table to something like 10 degress at running temps. See if the log bottoms out at 10 deg instead of 1 deg. If so, that may help get you looking int he right direction. Just a thought...

[Maxspeed96ct]

ill try that as a test, but id like to leave tq management in my tune for WOT.

I'm going to try to make the min spark like 15 vs the current -15 it is now

[jmyers09]

I would strongly advise you add cylinder airmass to you logs since timing is referenced off of it. I suspect you dipping into this region of the main timing tables. try adding some timing in the area is circled and retesting. high octane table.PNG

[realcanuk]

Idle needs to be tuned properly or idle adaptive timing will do that to try and hold idle speed.

[Maxspeed96ct]

Could you please elaborate? I had the fuel trims within 3 or 4 . I think even leaned it out in this tune/log to see if it helped.
No difference.

I really chased my tail adjusting the throttle follower and base airflow, i feel like I tried everything with that.

I was confident in the follower but it didn't seem to make up a difference.


Last night I bumped up the coast down timing, high octane and low octane spark in the 1000rpm and below range .
Still dipped very low.


This morning I set the min base spark to 15* in the 500 rpm range and 10* in the 700 rangers

No idle dip, watched the timing dip to about 11~12 degrees.

I feel like this is a bandaid for now, I'll do some more logs this weekend with some additional PIDS, if anyone has any good ideas on what to log let me know.

[realcanuk]

Try going through this procedure carefully... it worked great for me...

https://www.hptuners.com/forum/showt...103#post136103