engine Stalls randomly,and It does crank over. on 1999 Cadillac Escalade

Is the fuel pump randomly bad then good?
Cause if I wait awhile, could be 1hr or
3hrs.. It starts!
Is the emission sensor a culprit To this problem?

Asked by for the 1999 Cadillac Escalade
could be fuel pump or other issues seek diag as not to waste time and money
Good idea, thanks
1 more answer , 2 more comments
Could be a fuel pump; Several years ago had one doing the same thing. Tested the ignition system, computer system, no problems, still died while driving. Finally attached a fuel pressure gauge and took it for a ride. Sure enough the pressure would drop and the engine would die. Pull over and it would start right up with good fuel pressure. Drive a little more and pressure drops again. Changed the pump & filter, no more problems.
Thanks I feel better about what to do..
This helped me out.