I have a GTA with a stock L98, with the exception of a ZZ4 cam. I'm running a stock AUJM $6E .bin right now and it runs great. Ive only noticed one qwerk, when you are in park (or neutral) and you just rev the motor up and then let off, the motor will sink really far in the RPMs, run really rough and almost stall. Then after a couple seconds it smoothes itself out. The wideband doesnt show anything out of the ordinary fuel wise.

Is this a well known shortcoming of the stock $6E bin, and if so, how do I address it?

 

You should increase the Desired Idle Speed vs Coolant Temp Table as well as reset & adjust the IAC in the TB so it runs just 50 rpm less than your lowest Desired Idle Speed (that you just set).

 

I'll give it a shot, thanks!

 

You may also want to raise the RPM thresholds for DFCO, and/or increase the DFCO Exit Stall Saver PW.

I remember my AUJM'd car would do that too (and actually stall), strangely (about 3 years ago now, been gone a while). It wouldn't happen every time, and there were some "modifications" to the wire harness that I had suspected. I never had time to work on it though, and it only happened if I revved really high in pk/neutral, and let it drop. That technically isn't supposed to allow DFCO (speed less than 15mph or something), so it could be an IAC setting that is allowing the PID to close the IAC too much.

The XDF attached has a few more items to adjust than the standard xdf floating around... feel free to use it (anyone).

 

Thanks for the updated xdf file!

My car will do it almost any time you rev. Even if you only rev it to like 2-3k. It will run really rough, like it dropped cylinders, shaking the car and all, chugging bad out the exhaust. Then it will slowly smooth itself out.

I already have my idle set screw at its maximum extension so I cant get any more minimum air setting.

Argh

 

Check out this movie... this is in park in the garage:

http://www.mattodoom.com/hosted/almoststall.wmv

The raise in RPMs at the end to ~1500 is me giving it a tiny amount of throttle. This seems to bring the cylinders back to life if you run it at 2k ish for a few seconds then slowly let it back down to idle.

 

Once the RPM's drop low the stall saver kicks in. In this case the SA reverts back to the base timing, which is most likely causing the chugging, etc. Search for a thread originated by me, about stall saver on $8D (the $6E code is the same in this area). That thread has the info on how to disable the stall saver SA.

To keep the RPM from dipping so low look into the IAC throttle follower (TF) stuff. I can't recall what is available on the $6E for this. What TF does is to open the IAC as the TPS increases. Then as the TPS decreases it closes the IAC back down. However, there is usually a delay before the IAC starts to close, along with it closing at a slow(er) rate then when opened.

RBob.

 

RBob,

I followed your suggestions in this thread:
https://www.thirdgen.org/forums/diy-...ver-sa-8d.html

However, now that the stall saver SA is "disabled" the motor simply dies after you rev it up.

The idle set screw is at its full extension. With the IAC motor fully closed the motor idles at 700RPM. The lowest commanded RPM in the idle rpm vs coolant temp table is 750.

What's next? Throttle follower stuff?

 

Problem solved! I've been sitting out here in the driveway working on it. The problem was the spark advance table. There is a big flat spot in the stock AUJM under 800RPMs it rapidly drops off. I upped the low RPM timing quite a bit and now it revs great and comes right back down to a smooth idle. I also eliminated the stall saver spark (thanks RBob).