Any great cummins diesel guys on here?

problem solved!!
did more testing, and found if i blocked #4 injector line off the truck would start right up, did this to all cylinders and tried starting after each injector was blocked,
truck would not start until #4 was blocked off, ordered all new injectors,connecting tubes,and fuel lines .
truck starts right up now.
# 4 was returning all the fuel back to the tank and not letting cp3 pump build enough pressure while cranking, on cold mornings
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