There are many mysteries surrounding Lloyd's father as he is never seen in the series. He is actually only referred to once by Eddie when the gang (with the exception of Lloyd) talks about going camping with their Dads. Eddie then pauses and apologizes to Lloyd for talking about their Dads "with your Dad not being around and all."
It is unknown whether Lloyd's father passed away or if he left his family.
I Think he left his family in 1991, and died in 1996.
- Lloyd Nebulon (Son)