Engine works when it wants to

[jdub 357]

I had purchased a new fuel pump and installed it. My truck ran fine for a while. I went to an appointment one morning and after i came out, it wouldn't start. After a while, about 45 minutes, it started up. This seems to be getting worse. Any ideas???

 

[98trck]

my '98 5.7 sierra did something similar,
I found the wire plug at the distributer loose