1997 Z71 problem

I have a problem with my truck (1997 5.7 motor and 4l60e) it seems to be a small miss when sitting still at a red light...its not really a miss just the smallest drop in rpm maybe a hundred rpm just for a second..no codes just started happening, it has had tune up,wires,distributor,air filter and fuel filter about 3 months ago...fuel pump is about 6 months old from dealer (delphi) I just started noticing the problem...sometimes in the mornings when you crank it up it will idle for 2 seconds then its like you turn the key off...crank it back up its just fine for the next few days there are no codes and the check engine light works..thanks for any help

I have a problem with my truck (1997 5.7 motor and 4l60e) it seems to be a small miss when sitting still at a red light...its not really a miss just the smallest drop in rpm maybe a hundred rpm just for a second..no codes just started happening, it has had tune up,wires,distributor,air filter and fuel filter about 3 months ago...fuel pump is about 6 months old from dealer (delphi) I just started noticing the problem...sometimes in the mornings when you crank it up it will idle for 2 seconds then its like you turn the key off...crank it back up its just fine for the next few days there are no codes and the check engine light works..thanks for any help

What is the fuel pressure readings?