Sounds like kernel. Have you installed the boot.IMG from your custom ROM before flashing the ROM in recovery?
From fastboot install the boot.IMG do this:
You pick it out and extract it from your custom ROM zip.
Put it in your adb with fast boot.exe
Boot your phone into the bootloader (fast boot)
Plug in USB to PC and phone
In windows, open a command prompt and direct it to your adb with boot.IMG. "CD c:\adb" or wherever you placed your SDK or fast boot tools.
Type in command prompt "fastboot flash boot boot.img"
It should write your boot image and finish with a big OK!
If the kernel you're using is a zimage, you can Google a tutorial on zimage to boot.img
Boot in recovery and do all your usuals for ROM flashing. In recovery I usually wipe/factory reset, wipe cache, and dalvik . then flash ROM.
This is to ensure you have no issues with your ROM by flashing the kernel it comes with.
I'm still fairly new too but, if I have had any bootloop issues or random restarts, its because of the kernel.
Hope that helps mane!
Sent from my One S using XDA Free mobile app