Did a little searching on jaboticaba:
From:
http://www.daleysfruit.com.au/forum/jaboticaba4/"to induce early fruiting ringbark second half august any 3-4- year old limb provided tree is meter high"
And here:
http://www.cloudforest.com/cafe/forum/62073.html"I have induced another slightly larger tree to flower and fruit at about 5 years, by cincturing some larger branches. They do repair themselves quite well."
And:
http://www.rarefruitaustralia.org/2005/12/12/put-jaboticabas-on-your-list/"In many Australian conditions, seedlings can bear fruit as early as three years after planting, and can be induced to fruit (if taking longer than this) by ring-barking. This can be done when the tree is over a metre high (3-4 years old), by randomly cincturing the odd limb. This ringbarking disturbs the natural flow of plant hormones causing treated limbs to throw out flowers and fruit. August is a good month for your first attempt. Jaboticabas have an extraordinary ability to heal over such wounds, so don’t be fearful."
Sounds like the month you do it is important. I don't have much experience with them since I killed the only ones I had fairly quickly, but what about holding back nitrogen and giving extra P & K? Lots of trees flower profusely when they think they are going to die, so maybe you are just taking too good of care of it? I've heard of people hitting trunks with a baseball bat, or what about root pruning? Anything to stress the tree a little, but maybe that won't work with this species.
Regards,
Sven