what I tried:
First I wiped Dalvik cache and cache -didn't help
then I wiped Data -didn't help
then I wiped everything think I would get back to the stock loader.
so stuck in twrp I tried the LG support tools in windows but the program failed to find my phone.
I tried LGflash tools settign the phone driver to port com41 that also failed to detect my phone
all failed so I booted up my Debian OS managed to get adb push to work:
sent twtpv2.7 to /sdcard and ran an update
tried cm-11nightlyd02 with gapps then kernel-v3.3lgd802 -no luck
wiped everything again and installed:
testD802 80220B EUR Open.zip then KK_d802.zip then UPDATE-SuperSU-v1.93.zip
and after that no luck still in a boot-loop and not able to access download mode (vol+ and usb) tried draining the battery too
Please someone help, I think there might be some root system file missing
EDIT: fixed downlaod mode with:
abd shell dd if=/dev/zero of=/dev/block/platform/msm_sdcc.1/by-name/fota