+0

I think it's time I told you something I should have told you a long time ago.

Why not "I tell you something" is used.

+1

The idiom requires the preterite:

It's time we did something about it.

It's time you saw that great movie. (Also: It's time for you to see that great movie.)

CB

+1
virat1971

I think it's time I told you something I should have told you a long time ago.

Why not "I tell you something" is used.

American English uses both. Even in that variety of English the past is used more often.

CJ