They can indicate reversals, but they DON'T tell you WHEN the reversals will happen.
I ran into the exact same problem learning to trade based with fundamentals. Took me a while to learn that trading based on fundamentals requires a different approach if you want to get in early, which I will not go into here.
The fundies are still pointing upwards on USDJPY, but as you mentioned you have to trade YOUR system.
But this has me thinking if having fundamental analysis on this thread, is taking away the focus from technical analysis.
-Razorjack