Hello.
Currently we have no eMMC pinout for this device, but You can try to connect it via USB and, if connection will be successful, do "Factory Repair".
To connect the phone via USB, try to do the following:
1. Install the latest Octoplus JTAG Pro Software version (
https://octoplusbox.com/en/download/software/).
2. Select "USB" interface option.
3. Select "Brand: Custom Settings".
4. Select "Device (Core): Qualcomm MSM8909".
5. Select "Loader: QLoader_v1".
6. Connect the phone to PC in "Qualcomm...9008" Mode and press "Connect" button in Software.
7. If the phone will be connected correctly, do "Factory Repair" ("Factory repair" tab in Software) using the latest original LG firmware for this phone.
8. Disconnect the phone and try to put it into Download (Emergency) Mode and re-flash it using LG tool.
9. Post here the result.
There are a few USB loaders for Qualcomm MSM8909 CPU in Software. Try also to connect the phone using each of then. You should re-connect the phone before trying to use new loader.