CM870 Boost problem?

[B model]

cm870 actuator moves freely and works when tested on Insite. Sensor tests showed normal??
This is a what I would call an intermittent problem sometimes it just drops out and wont boost any. If you are like cruising down the big road its fine, pull off on ramp, when you turn its gone.
It will come back if you drive it a little bit. Is it possible for the actuator air control to have intermittent issues??