03 7.3 Hard Time Starting

[malibuman82wgn]

have a 03 7.3...been having problems starting for couple months now...sometimes it does it, sometimes not...when cranking over white smoke comes from exhaust and when finally starts (6th or 7th try) a BIG cloud of white smoke follows...was told it was injectors...is that the only possibility? few months ago an employee put gas in the truck and was totally cleaned, etc. etc...if it is just injectors would it be best to replace with stocks or upgrade? thanks