I have a 94 blazer W engine . I've been having issues with a rough idle when I start it up in the morning but it goes away when warm. I did a fuel pressure test everything was ok . Today I was breaking hard and it stalled , it has less then a 1/4 tank of gas . It started up right up afterwards . I've been holding off changing the fuel filter its still winter here .

 

all the fuel could have gone to the front of the tank causing the pump to not get gas temp.

You say you did a fuel pressure test, what were the results?

 

KOEO 60 psi, idle 56ish i let it sit for an hour and it never dropped lower then 54

 

That's fine for your Vortec. I agree with the prior comment, as this happens in my truck as well, which is a non vortec TBI. I think the gas is sloshing beyond the fuel pump pickup.