1982 300 TD Conversion

Ok - I installed the kit - have no oil leaks and no audible vac leaks this Sunday. Monday I was running 90% pure diesel with 10 % veg oil. I drove over 75 miles with no problems whatsoever. (As it was such a small proportion of veg oil I did not believe I needed to switch on the heating element.)
This morning the temperature probably dropped to about 45 degrees. I live in the Bay Area and usually it does not get too cold. Again thinking that the high proportion of diesel would again not justify the use of the heating element I started and drove off. My car seemed to have about 40% of the power it normally has and 50 yards later stalled and came to a halt.
I checked all lines and the clear in line filter and saw no debris or leaks.
I tried to restart after turning on the system and waiting 5 minutes. The car still would not start. I then turned off the system waited 7 minutes.
It looked like a little air had got into the clear filter - I bled the large filter and reprimed the system. After cranking the engine..the engine caught and I keep feathering the accelerator and was able to get the engine to maintain an idle...I then drove the car 5 blocks - but preferring not to get caught away from home. I parked it and took my wife's care to work. Any thoughts about what might be going on?
All advice greatfully recieved.
Also -- the oil that was added was filtered, non hydrogenated rice oil. About 1/2 a gallon.