8.1L Throttle Surge

[MoTruck]

I have been doing some basic tuning on a 8.1L with the Allison. I have only worked on the the PCM side. Basically, I played with the timing and burst knock. I also tried to eliminate torque management. However, now, shortly after it shifts gears, I get a throttle surge like the area circled in the attached log. Basically, something is giving it a quick burst of throttle. Any ideas on what would give it such a burst? It runs well accept for an occacional throttle burst. Thanks, Dallas

http://i79.photobucket.com/albums/j135/djthompson/th_Logshot.png (http://i79.photobucket.com/albums/j135/djthompson/Logshot.png)

[Tordne]

Have you just noticed this start after going from MAF to Speed Density tune?

If so.. Check the Desired Airflow table B4307 and probably do the idle transition (search for RAFIG) tuning stuff.

Also perhaps check the Throttle Cracker and Follower settings and decays.

[MoTruck]

Thanks for the thoughts. I did not ever tune it in speed density. I added a couple of degrees of timing down low, and tried to remove the torque management. Could it be something in torque management? It usually does it immediately after shifts.