Have replaced everything
starter, plugs & wires, fuel filter & pump, battery. After not starting 2 or 3 days won't start. Sounds like going to but when let off key sounds like its chugging start pumping on the gas while trying to start and it finally catches and starts. As long as you run it everyday it will start first turn.

 

Sounds to me like you need a new battery. Don't forget to check your alternator as well. Seen lots of new battery's made in Asia, that cant hold a charge.

 

Have new battery

 

Do these have a fuel pressure regulator them? If so it might be allowing pressure to bleed off over time causing this. It happens with some Ford's.

 

Yes. All F-I motors use a fuel pressure regulator. You might want to check that out.