some times hard to start
 

my friend just has got his truck back together and sometimes it crankes a long time. what he had done to it is he had to have the motor redone bottom to top because he ran it out of fuel 2 winters ago and used starting fluid on it and when it did start it came a part. pistons, crank really everthing was bad. so now he has had it about 3 weeks now so it sometimes cracks a long time before starting what does he need to do? thank u. 6.6 motor 2003 chevy 4x4

did he change his filters and clean his sensors when it went back together ?(air filter, fuel filter, mass air sensor.....)

yes every thing new