LS2 tuning hard to start, DBW TPS erratic?

[HoldenTuner]

Hi All,

Im no expert in Gen4 tuning.
So this car is hard to start especially when warmed up, some weird startup surge and stumble at the right coolant temps can happen, though the engine would run once started up, anyway I seemed to be chasing my tail editing cranking maps with more fuel, less fuel, more timing less timing.
Then I noticed the Throttle Position in the scanner only in live view would have continual up blips, sometimes upto 10% movement multiple times per second, it didnt matter if the engine was running or just key on. Part and full throttle would have similar anomalies in it, Unfortunately it doesnt get captured in a log file but is clear as day in a live view, so I screen captured it and attached the video. You will notice the yellow graph moving while there is no throttle input, in the video its flickering from 19% tp 26%.

Is this normal or do I need a new throttle body.?
https://youtu.be/fiI_bK_2u78

[kevin87turbot]

You are datalogging both Throttle Position and Throttle Position SAE. I suspect the anomaly will go away if you eliminate one of those Channels.

[blindsquirrel]

Can we please get a sticky for 'Do not use SAE channels for GM electronic throttle PIDs'?

[HoldenTuner]

Hmmm,
nice bug, lucky I didnt order that throttle body.
Back to the old drawing [tuning] board.