new member here, made my living as auto technician since 1986 but not on diesels. Thats why i'm hoping some you powerstroke gurus can help me, long story short do a lot of work for a landscaping co. and they have a couple 7.3's in the fleet and they know i can the maintinace and external repairs (water pumps, starters, tstats ect) but as far as driveability i'm useless. they had been having starting problems already but called me to his house because of a bad fuel leak, found and repaired a fuel rail end plug on front of right head and truck has'nt ran since. do have a scan tool and alldata and scan data seems all is in order except i noticed the coolant temp sensor showed -40 degrees, i know on a gas engine a bad sensor defaults at - 40 and if car does start its flooding to death, so today i unplugged the cts and it actually tried to hit, did fire up for a couple secs and died, could the cts be causing an overfueling problem, and when it is tring to fire getting lot of white smoke. sorry to be so long winded but any help would be appreciated:

 

pull plug on top of hpop under plastic cover that you have to remove to change fuel filter.
take a 10 inch piece of wire see what the oil level is if it isn't pretty close to the top the
check valve is probably leaking oil back to the pan and the hpop doesn't have enough oil to pop the injectors will turn over but wont start.top off with oil and it should start until next time it gets low.caution the oil you add will over fill oil level in pan.

 

Good point in checking the HPOP reservoir. While you're at it, check the oil. If it ran low, the LPOP would run out of oil to feed the HPOP.