skytrak 6036 starts hard when temp below 60 deg

I just bought a2000 Sky trak with 4000 hrs and has the Cummins engine and it starts hard when its 60 deg or colder have to crank at least 30 sec or more.
From what I can tell the Cummings does not have glow plugs. Do you guys have any ideas on how to fix? My friend has the same lift with 7000 hrs
and it fires right up down to 30 degs
Thanks