Sean is indeed correct - I've been selling parts (locally) for over 20 years - the "J" is the tolerance code for 5%. The entire EIA code is:
F = ±1%
G = ±2%
J = ±5%
K = ±10%
M = ±20%
Now for POLYESTER film capacitors, there is a letter/number code for voltages - it is:
1H = 50
2A = 100
2D = 200
2G = 400
Happy to help,