Throttle body chatter

I have a drive by wire TBSS intake . I purchased the adapter to convert wiring to work with tbss from summit when you turn key to run position the throttle body chatters for about 30 seconds then stops checked pedal operation and pedal is opening and closing as it should but will chatter at wot or when released to idle position. Any idea whats going on. All grounds were cleaned and tied together at trans and block sanded everything before torquing bolt down This is going in a 90 chevy truck with a 5.3 engine 4l80 trans

Truck is now running chatter doesn't seem to cause a issue at this time so now on to other issues.

My 2005 suburban with a TBSS swap on a 6.0L is doing the same thing. are you still not having performance issues? I am wondering if I should do anything at all with it.