need help with my wife's 'burb...please

[manimal]

Ok, last friday my wife was driving her '89 suburban(2wd,454 TBI,th400) and it would just shut off,and have a hard time restarting. You can no longer hear the fuel pump priming(usually ran for like 2 seconds then shut off),the the car would start. Now it seems to crank and crank then finally start,but run for a few minutes and shut off. After the initial start,it will start(hard) run for about 15 seconds and shut off. I have replaced the fuel pump(in tank) and filter, the coil and distributor module check out just fine. I have swapped around relays, but now I am stumped. Can anyone please help me out? Thanks
-Lance

[BLE 'BURBAN]

fuel pressure regulator. Same thing happened to my old 87 astro van. Got a rebuild kit for the tbi unit, installed it and the thing ran as good as new.
Regulator is mounted on the top of the tbi unit.

[dropd80s]

Also might want to make sure you have power to the tank and to the pump. I bought a 91 sub that would not start, the terminals on the in side of the tank on the bottom side of the pump/sending unit assembly were corroded just enough so the pump couldn't get any juice.