Running perfect parked for the evening would not start in the mor

Not enough oil pressure to open the injectors. Check pick up tube

It is a clear case of the glow plugs malfunction. It had happened with my neighbor who tried to start his diesel focus one day.
Even jump starting with another battery didn't solve the starting problem.

You could also check the EGR valve for damages and if you want to save a couple of bucks, then go in for used parts for the focus from Good used Focus Stuff

fuel at fuel filter doesnt mean its getting the correct pressure to operate the injectors. do not spray starting fluid into a diesel motor, you will damage the rings, score cylinder walls, burn valve guides... etc . starting fluid is not designed for diesel engines. the only way to test the fuel system is to test it by hooking up a pressure test gauge to the service port. the next most likely issue would be a faulty glow plug relay or 1 or 2 faulty glow plugs.

I had the same problem in my Ford Focus 2.0 and the problem was gone when I changed the spark plugs and the spark plugs wires...

But if your car is Diesel maybe it is the EGR valve...

the low pressure valve is the longer skinnier one. The low pressure valve should be on the fatter of the hoses in the engine compatrtment. Try close to the compressor. if you stil cannot locate it i can check my service manuals or the exact location.

since this is a standard and you need to engage the clutch which basically shifts you into neutral to shift gears, this ALMOST sounds like the idle air control valve.

i have exactly the same problem, same model and year, car runs perfect but oil light comes on after 5 mins or so. its got me stumped!

the high pressure pump provides the pressure to your injectors so the diesel luel can be injected at high pressure. You should fix this immediately. Call your dealer and ask for some help from Ford on the repair cost ahead of the repair. See what they will do.

There is leak in the fuel system and air is coming in somwhere. Maybe the hoses with the injectors are leak.

Possible oil sending unit problem.