תרגום - גרמנית-אנגלית - ich würde gerne mit dir reden wenn du zeit hast.

Hey, you were faster than me!
It could also be "I'd like to talk to you WHEN you have time [for it]."
In German, "when" and "if" can be expressed by the same word, and here both possibilities make sense.

hehe, lucky me

Yes, I also thought about using "when" but finally decided myself for "if" - but you're right, both is possible. Although there's a little difference in meaning, its not clear from the context, which of the two is meant.