I can't seem pick up siri eyes free on my iPhone 7 to my 2014 Acura MDX with Tech pkg even though I am holding down the talk button. What do I need to do?

 

Make sure ALL the Siri functions are activated in the IPhone settings
Including, "Access when locked", 'Allow Hey Siri", "voice feedback", etc.
My IPhone 64GB/SE, works perfectly in my 2015 TLX/SH-AWD/Tech
FYI: You can actually SEND text messages, by commanding Siri through the voice activated system
It drove me, & Acura techs crazy, that "sending" was impossible with an IPhone
Thanks, Apple!
My BlackBerry Q10 was flawless with messaging; text, & email
Go figure

 

Assuming your previous iPhone worked fine sounds like your new 7 has some setting changes. If you've been so frustrated to come to the TLX forum to ask about your connection issues with your old MDX then probably it's easier for you to take the phone to a Genius bar.