6.7 won't run, possible turbo issue, need input.

[fireplanner]

Well I found it... the throttle valve is closing and won't reopen until the key is off. I removed the DPF block plate and it fired right up, realized it was an air issue and found the throttle valve is open until the key goes on and then it closes tight and won't crack open or reopen whatever it's supposed to do... unplugged it when the key was off and truck fires right up. Whats the purpose of the throttle valve other than for recirculation when using an egr? Any reason it would be closing? Pops right back to full open when the key off.