This plant seems to be having some kind of a problem, its growing normally thought. The new leaves ado not get affected ,but when they get mature the discoloration slowly shows up.
I digged arround the plants root perrimeter and it seems to me tha a vine with so much vegetative mass shoul have a thick mat of feeder roots near the base. I did not saw any...the soil is moist. I am thinking now that i have overwatered the plant and the feeder roots died off, which in return leads to it not being able to support its growth. I have had such things happen to different plants in the past...
Thanks for your opinion on the problem, i want to get the plants as healthy as possible since its starting to form flower buds and i will be self pollinating theese in hope for a fruit set. I'll quit wattering it, untill it shows some watter stress sighns, in case the problem is too much water.