1997 Chevy Suburban starting

With either the 7.4L or the smaller V-8's the fuel pressure regulators will do what you describe.They bleed the pressure down overnight then the system is full of air and has to rebuild pressure in the morning.Did you install a high quality pump as well? More than once I have had to go back in to repalce a less expensive pump for issues.Can you hear the pump run when you first turn on the key in the morning? Try cycling the key (on-off-on) a few times in the morning to run the pump a few times and then crank it to see if it builds pressure faster.Also may want to install a fuel pressure gauge to see exactly what the pump is doing.

my fuel pressure is ok have checked. i put a new not rebuilt fuel pump , so if I understand you think the regulator is bad and leaking down over time. If so a new valve should correct problem

If it is the regulator then it can be repalced for a resonable cost.Have you checked fuel presure in the morning when this is going on? What psi was the pump at and how fast does it bleed off if you turn key off? what size engine too please