I have a 98 blazer 4.3l and it will start and run for a few second and then die. I have checked the fuel pressure and i am getting 63 psi and i have checked the relays and they are good. I put about 5 gal of gas because the gauge read E and the gauge still did not move if and body can help please do before my wife make me sell it.

 

add more gas

Its a known issue posted here before about being under 1/4 tank and having run issues.

Try that first. If that does not help then have to dig deeper into it.

 

is security light on ?

 

I know you said you already checked it, but I would try swapping out the relay in the electrical center under the hood. There are a couple under there that are the same relay that you can swap it with . What you are descibing is exactly the same thing my 99 did a couple of months ago. Start fine, run for a couple of seconds and die. Would do it every time. I was at a retirement party so I was stuck but I lucked out and got a call from my brother in law who knew what it was. Swapped it with a headlight relay or something (don't remember exactly but it was the same relay) and it ran like a charm.

 

i have a 99 with same problem, got it running today .i dont know if your interior lights are off also, and under hood light, rear hatch button? if they are look tbc fuse under hood by relays look good mine was blown and didnt really look like it. its 10amp.

 

i put ten gallon of gas in it and it does the same thing. I replaced all the relay in it and still nothing.
i do not see a securty light where is it located at.

 

It's right on the dash in plain sight. If it was on you would probably have noticed it already. Sure sounds like the computer shutting you down somehow. I'll look through the service manual and see if there is anything related to the fuel sender that could shut you down since you say it's showing empty. This stuff is great when it's working but what a headache when it's not.