Just came across this post after searching for a solution as well to import CSV into a Custom Post Type with ACF fields in it.
I found this one:
http://www.smackcoders.com/wp-ultimate-csv-importer-pro.html
The free version, downloaded from the plugins section works pretty nice, and seemed to allow me to select ACF based posts, but wont import. They say the paid version (which is a bit pricey per domain) will work with ACF based fields. I’ll let you know when I get the pro version installed.. really hoping it works for that price.