Ok, I fully charged the batteries and ran the heater block for 6 1/2 with my generator. Temps started at 19 degrees and warmed to about 42 after that 6 1/2 hours. Did not start on 1st cycle, but it almost hit. 2nd cycle it fired up & has settled out to a good idle. I am going to let it warm up good and then run it down the road. This should rule out air in the system and the lift pump right?