Starting Difficulty on 1996 Chevrolet Astro

I have 1996 Astro that is having trouble starting. Once started it runs great. I have tested the fuel pressure and is above 60 psi before starting. I have replaced the fuel filter, plugs, temperature sensor/switch, oil and filter, and serpentine belt. What would cause difficulty in starting and then runs great after. Vehicle starts immediately after running up to two to three hours later. Hard starts again after sitting or in the morning. I am thinking about switch ignition module next.

Asked by for the 1996 Chevrolet Astro
Is sounds like your fuel pump is failing. The fuel injection system on your Astro van needs slightly higher fuel pressure in order to start. One the engine is running it will operate normally on lower fuel pressure. Double check your fuel pressure test - make SURE the pressure is over 60psi when you turn the key on - it will drop slightly after a few seconds.