The problem started the day I was driving during a heavy rain storm. Not sure if it was related or just a coincidence.
The engine just stopped running. I was able to restart but it will only run for a few seconds and stop. The following items have been changed or verified ok with good components.

Fuel pump - Changed
MAF sensor - Changed
Crank Shaft positioning sensor - Changed
Fuel pump relays – verified ok

With a fuel pressure gauge attached you can see the pressure go up to approximately 50 psi when the key is first turned on. As soon as you start the car the pressure drops and stalls.
There is two ways I can keep the engine running.
1. If I hold the accelerator pedal full throttle the pump runs building pressure and the engine stays running. The psi drops the moment I start to decelerate below the rev limiter.
2. I can make the car run normal by jumping across the normally closed contact (forcing it closed) on the fuel pump relay (spd cont), I think it’* labeled # 19.
I don’t know where to go from here. Don’t want to keep adding unnecessary parts.
Any advice would be appreciated.
2000 Buick Regal GS
3.8 SC

Not heard of this problem on vehicles with the 3.8L, but on GM'* with the 4.3L, the fuel pump ground wire corrodes and causes the fuel pump to intermittently stop.

I didn't see mention of the Fuel Filter being changed?

if he can get it to run normaly by bypassing the relay everything from there back is good
i dont have time to go through the drawings now but either the pcm isnt calling for it to run or you have an open from the pcm to the relay

Pcm is calling for fuel at first turn on of the key. Otherwise he would not get the initial pump prime to 50psi. He needs to verify via a test light on the pump wires to see if its being shutoff or if its somewhere else.

thats right. it must be good so what what would cause the pcm to prime and not run after?

this is the one with the funky resistor and if that opened i think it may do something like that

https://www.gmforum.com/regal-181/99...stalls-302844/

Jwfirebird, I think you on to something with this resistor. Called one local Gm dealer and they didn't know what I was talking about. Auto parts store didn't have it listed either.. On my model I'm told its hidden behind the washer reservoir. I'll track it down and check it out. Thanks

As turns out it was the resistor. Found the ceramic had cracked in half. The new kit from GM has you relocate on the firewall. Thanks for all your help. Today I'm going to tackle the heater / AC display which hasn't worked in several years.