If pump is running it's supposed to be pumping gas. I thought all lines to pump were different size tubes. I would run it with lines off but with rubber tubes into a gas can and see if it pumped gas. That's how I emptied my tank off test valve on motor.

 

Understanding I'm talking to myself while people watch however I may have shorted (hopefully) the fusible link to the ecm. I now don't know where that is. Any help greatly appreciated.
Edit found this pic under vcm issues, relay cluster https://blazerforum.com/forum/attach...l-img_2525.jpg

 

Off an s10forum "Sorry I'm a little late on this topic, but a few weeks back I had a PCM go bad. I fried it when I tested the*fuel*pump by jumping the relay--only I got the pins backwards and jumped the PCM instead of the pump. As ridiculous as it sounds, I'm smarter than that. Usually." Eh it's only 200.00

 

I purchased a brand new Tank and Pump once,(they are a pain to put in). Finished install and Blazer would not run. Checked everything ( Always have someone listen for pump to actuate). In my case pump was in fact wired properly and working. After many complains to Vender it was discovered that there are actually two possible pumps for that Vehicle. I forgot which Blazer it was I have had 13 different years. That particular year had two possible pumps and you will not get the pressure you need unless proper pump is installed. Before you have to take that puppy out again dig into the proper pump for your Vehicle. Once Installed the proper Pump I never had a problem again.

 

Forgot to mention the oil pressure switch controls gauges on some models. Mine was broken but barely connected I replaced it got gauges back as well. Pump won't run without it. But should be able to test it.