would you answer a question?

[Unregistered]

what's the difference between 1 and 2?

1, If I have time, I would help you.
2, If I had time, I would help you.

[Casiopea]

what's the difference between 1 and 2?
1. If I have time, I would help you.
2. If I had time, I would help you.

First, sentence 1. is incorrect. You should replace 'would' with 'will', like this,

If I have time, I will help you.

Sentence 1. is an example of the 1st conditional:

If + Present tense verb + will

Second, sentence 1. refers to the Present. The speaker is saying that if s/he can find the time to help you, then s/he will definitely help you. Sentence 2. refers to the past. The speaker is saying that s/he has already decided that s/he doesn't have the time to help you, so s/he can't help you, but if she did
(Past tense) have the time, then s/he would (Past tense) help you.