Hello all!
Thank you all for leading me in the right direction, the PSU.
I don't know how many hours I spent troubleshooting this, but now it seems to work!
I did the following
1. Added another cable from the PSU to one of the cards, so each cable has two PCIe connectors, I added one cable and used one of the connectors on one of the cards.
2. I changed power outlet for the computer, just put it in another outlet. I used the same connector in the wall where I usually connect a BBQ, so I know that has plenty of power

I now do around 600khs per card, which is fairly ok.
I will do some testing with underclocking etc now that it is working properly and no more 80khs.
THANK YOU ALL!