No need to go further. If the regulator is good and the correct one then the pump is bad.

put new A/C Delco fuel pump in 2 days ago. car still stalls. but I'm pretty sure I have an electrical issue. I had a code recently that said my Data line was shorted to batt. I did a little trouble shooting and everything checked out normal.
But check out this video. click engine dies link. this just happened Friday right as I came to a stop. Note how the speedo jumps right as the car dies. and the 2 idiot lights flash too.
The ABS light has been on and off for weeks now with no code present, but a code for ABS pump failure or something is in history, I don't remember the code.
So I'm kinda back to square one, except at least now I know it'* electrical.
I'll let you know what I find.
engine dies

The link just goes to a 404 page not found error.

I'll try to repost it.

try this one.
https://photos.google.com/photo/AF1Q...smJg6zWPW73Wx8
codes I have today.
U1000 class 2 data link malfunction
U1088 loss of SIR/Sensing and diagnostic module (SDM) communications
U1064 lost communication with body control module
P0452 fuel tank pressure sensor circuit low voltage
U1026 loss of class 2 communications with ATC
U1152 loss of heating ventilation and air conditioning communication

Same 404 error.

All of those codes look like a communication problem. I'd go through wiring on this. Looks like something is flakey.

sorry that you can't see the video. Don't know why. I can click on the link myself and it works but that doesn't help anyone else.
with all the codes and the intermittent nature of the problem I was thinking the same thing. I've checked some harnesses and wiring already, including the ECM connectors. I'm gonna do more but the problem is that it'* intermittent.

Have you cleaned the grounds good.

I checked all the grounds months ago. some were rusty and I cleaned them. I'm going to double check, I may have missed one. something weird is going on with this Trailblazer.
I have a busy week ahead but I will check back when I find something.

OK, 3 weeks ago I reset the throttle body. It still stalls at stop lights but not near as much. It seems the longer I sit there the more the chance it will die. It never happens right when I come to a stop, only after 7 or 8 seconds, sometimes longer.
So here'* where I sit. Only code I'm getting is intermittent lost communication with BCM.
I may have 2 separate problems. A Bad throttle body. And a BCM wiring problem.
The Throttle body is giving erratic readings sometimes. Wires and signals are correct checked with multimeter but scan tool shows % throttle requested and actual way different from each other.
I took my seats out today and pulled up the carpet. took out BCM and visually checked every connector, cut open all the harness' and checked wires and all looked ok. checked for continuity on data lines from splice in back seat to BCM and to other splice under dash. all were good.
There is a connector that connects the BCM to the rear fuse box. It is flat. When I worked in electronics we called these ribbon cables, GM may call it a Flat wire or cable. This may be my BCM problem. It'* kinda loose and I see no way to fix it. The BCM should have no effect on idle as far as I know. Correct me if I'm wrong.
I may buy a new throttle body and BCM cable if I can find one.
Just wanted to let you guys know what'* going on with my Chevy from Hell! I will fix this if it'* the last thing I do!!!!!
till next time. bye