It was about -15C (5F) this morning when I tried to start my 79 240D. I have a block heater and had it come on by timer about 3 hours before I needed to start it. I pre-glowed the engine and cranked it over.....started up pretty quick, ran a little rough then smoothed out...as usual in the cold weather. After about 2 minutes of idling it started to shudder and finally stalled. This happened to me a few times in the month. I thought it was the filters so I changed them all a few days ago. I thought they might have been dirty and the fuel was too thick for them in the cold. I also have a WVO kit in my car mostly set up for the winter. If it starts to stall I switch to the veg tank and put on my fast electric fuel heater and it will usually keep running at an idle. I do this until my coolant is all warmed up then I can just drive on Veg but it was too cold this morning and it wouldn't draw the cold veg from the tank without coolant heat, so now I have a car that won't start...and the possibility of cold veg in my injectors. Any idea what it may be? I am thinking of getting a coolant heater to supplement the block heater. I have not owned a diesel in the winter before, do you think the fuel is just gelling?

thanks for any help !

Will