is it possible to have the gps location while offline with the nexus 7? This is a mystery to me, I know that WiFi and GPS use different chips to work, but it seems I can't use the GPS location when there's no Internet access.

I already tried to clear the cache, disable/enable it, reinstall it.

I just want to use my nexus 7 as a GPS while I'm out, thought that I already downloaded Google maps offline data.

Is it supposed to work while offline or not? Is it a real GPS?
I had this issue - it isn't that a fix doesn't come, it is just that it is taking a very long time to get a fix.

This is due to the lack of the downloaded aGPS data - it can't download the data, and so has to rely on solely GPS satellited, which takes ages.

If you have been disconnected from the internet for a while, then you will suffer from these effects. aGPS data is cached for a few days, or when you change location, so if you just disconnected, GPS should work for a while afterwards. 

(You should also check to make sure that the Google System is enabled for location use)