LS3 Need LS Guru help

[robbbc]

Too much airflow can give a cruise control type of feel. Possible that there is not enough base running airflow until you hit higher rpm? Again, without looking at a log or tune; it is just speculation. Fuel multipliers are at play based on engine coolant temp, intake air temp etc. Spark tables add or subtract due to engine coolant temp, intake air temp etc; so its going to be tough to pinpoint what the issue is without having that data on hand. Even the intake valve temp comes into play as to if it will add or subtract fuel. That could be why it changed sound while at idle.

[streetk14]

I agree, but this was a stock GM tune file that was supplied with the crate motor. While my experience has been that those tunes aren’t great (no VE tuning, stock spark table, etc.), it shouldn’t be doing that. I think the check engine light and reduced engine power mode are the key here.

[robbbc]

Agreed, streetk14. Sounds like there is an issue with the throttle settings. Not sure how i missed the engine light and REP mode. lol