Definitively chain & tensioners.
Try with 20W50 Oil, it goes a little bit better (for a short while).
But you have to change both tensioners, the chain and in addition the 2 curved guides soon, before the chain will spring over
Tomorrow Im heading to the Mazda infected area to buy me the mazda chain tensioner 3953-12-500A which is suggested in the FJ20.com engine tech section.
What do you mean bij the 2 curved guides? Any pics/ more info?
Thanks for your help guys. Appreciate it.