Fuel pump not working

I have a 2002 s-10 blazer. My wife went to the grocery store and the car performed fine after coming out of the store the engine would turn over but not start. You can shoot some starting fluid in the intake and it will start and run till the fluid is gone then it dies. I have changed the fuel pump relay, inline fuel filter on the frame and the fuel pump. The new fuel pump is still not pumping fuel. All applicable fuses are good. What else in the system can cause the pump to not function? All wiring looks good visually but I have not run a continuity test. I was short on time and was trying to get it up quickly so I was part swapping. Is there a relay that I am missing in the system or what conditions would cause the computer to prevent voltage from being suppiled to the pump? The motor will run on starting fluid so at least that part of the ecm is working. Any thoughts would be appreciated. Thanks.

2002 S 10 Blazer 2 dr with a 4.3 TBI. Fuel pump quit working replaced fuel pump and still won't come on. I read the book and it says that if oil is low the fuel pump will shut off added oil and still nothing. I checked the relay and the fuse box and am getting power to it there is one in the glove compartment not sure which one it is? What else should I check?

I have power at the 20 amp fuse (ecmb) but do not see a gray primer wire. Where would that be located.I see it on the wireing diagram just not on the truck or sould I pull the relay out

Do you know where the fuel safty switch is located? The dealership said to chk it first but they didn't show it in the book where it's located. P/s And I just like to say thank you for your help