low pressure fuel /glow plug light

car wont start and glow plug light come on , engine has been checked no mechanical faults found.

now car is showing low fuel pressure on OBD  and glow plug light is on. 

before car broke down there was a rattling noise coming from the engine when car reached 30 to 35 mph , suspected injectors - no codes came up.

car never struggled to start or misfired prior to breaking down , can it be fuel pump or injectors?

any advice will be greatly appreciated!🙌