[Vwdiesel] Was stalling now not starting

[Fudny at aol.com]

Previous question to the list was my 85 non-turbo Diesel Jetta would just
power down and stall after driving 2-3 miles, after stalling, starting 2- 3
times it would run
the rest of the day no issues.
Now we have reached outside temps in the teens and it wants to start but will
not continue to run. I have now added a seperate fuel filter, (small
container vented for a fuel tank) and a separate container for return.
Installed all of this in the engine compartment to eliminate anything with
the fuel tank and lines. The pump doesn't seem to be pumping much fuel and
the return line has very small pulses of fuel.
Does anyone have a clue? As of Wednesday it was running fine. The following
morning (temp outside 15°) will not run.

Ran tank almost empty, previous check of tank showed no signs of algea or
foreign material.
Blew out all fuel lines - they are clear
I replaced my seperator with a used 86 donor.
Check valve seems to be very hard to blow through.
I am thinking maybe I have ice in fuel pump? injector line? pump timing?
The fuel solenoid clicks. Could that be blocked?
........... scratching my head!
TIA,
Terry

85  2 dr Jetta Diesel
86  2 dr Jetta Diesel
78 - 300 cd mb