I have this ongoing issue (CC2014) where there is a really long delay before rendering starts. Nothing fancy or heavy, no effects, MacPro/Yosemite/64 gigs ram, rendering to internal SSD. I sometimes see a 2, 3,4, 5 minute delay before rendering starts, then my short, simple comps render in seconds. Just AE text, shape layers, and placed AI files. No network stuff, no other apps running.
If you're using multiprocessing, turn it off & see what happens. If the wait time goes away, you may have to reallocate your processors & memory for multiprocessing in AE Preferences.
And it never hurts to purge the memory & caches before a final render.
It seems that might have fixed it - thanks!. Now the question is how that got turned on in the first place as i am sure I tuned that off a long time ago. Probably some pref reset happened at some point I guess.