My 98 is having a fuel pump issue. It all started a couple weeks ago, when I was out running errands and came out after spending around 45 minutes inside a store. I came out to a no start and right away I started diagnosis. I couldn't hear the fuel pump, a noise that I have become quite familiar with as I had fuel issues with my previous 96. After a few minutes, the pump started working again. I thought at first, maybe just a fluke. It started just fine till that night after I worked 8 hours. Again, no fuel pump running. It started after a few minutes so I drove home, went out the next morning and had the same issue. I swapped out the fuel pump relay with the horn relay and everything worked fine. Problem solved. So i thought anyway. Yesterday while out running errands, i stalled in the middle of the road. Pulled to the side, and there was no fuel pump noise. This time, I could not get the pump to get any life to it like previously. After waiting for the shop to look at it and verify what I thought for sure was wrong, they got to looking at it today where it started right up for them and worked just fine. They let it sit for a few hours and went back to it where it started right up again. Any ideas?????

 

Sounds like you need to do the fuel diagnoses that is posted on this site. "Hearing" or not hearing the fuel pump is not the correct way to diagnose the fuel pump. These vehicles need a lot of pressure to start and stay running! Get a fuel pressure gauge on it, or have a shop diagnose it (when its acting up that is). If you search this forum you'll find many stories similar to yours regarding fuel pump issues.

 

I know the fuel pump isn't running when I am having this issue. When it is working properly, you can hear the fuel pump hum. I have been around long enough to know when a pump is working or not. I just like to cover all bases when it comes to things.

 

Like I mentioned, the fuel system diagnoses should be done... And yes, the fuel pump could be running even when you don't hear it, it just may be so weak you're not hearing it run
Here is the link:
https://blazerforum.com/forum/showthread.php?t=45941