Would + present tense usage

Question

Is this sentence correct?

When she comes back, I would tell her.

I know this is correct, because the would acts as the future tense of the past tense.

When she came back, I would tell her.

Answer 1

I can't make any sense of "When she comes back I would tell her", unless it is followed by something like "but I can't because ...".

The second version, "When she came back I would tell her" is a bit more comprehensible, but still only makes sense to me in a couple of contexts:

1. This is a narrative about my intentions in the past, before she came back. Something like. "I thought about this for a long time, and eventually made up my mind: when she came back, I would tell her".

2. This is a narrative about habitual action in the past: Every day, she went out to work, leaving me a something I was supposed to find out. When she came back, I would tell her."