Have not solved it yet. I can tell you that on my engine when your replace the spider, the FPR is also replaced, its 1 unit, so that didnt fix my problem.

I ordered an AC Delco pump from ebay and I am gonna replace it this weekend.Hopefully that does it.Mine drops pressure at the filter so hopefully its the check valves in the pump.I will let u know what I come up with.

I have a feeling I'll be getting my pump replaced soon. Pressure no longer drops, but doesnt appear to build enough pressure to start. Only up to about 48psi. A shot of starter fluid and it fires right up and will run all night long. Any other thoughts of what this could be?

fuel pump fixed mine
 

I put an ac delco pump assembly in mine tonight and it fixed it.Found on ebay new for $159 shipped from a company named Alanis Deals.That is the cheapest I found anywhere.Dont fall for those cheap 50$ ones on there.Good luck and if youronly building 48 psi it will not start that truck.

Fuel pump replaced..... truck ran. and just in time, cause my other car dumped its water pump. Ran the blazer for a week. Now the oil pressure gauge is reading Zero, and check gauges light is on. I'm thinking its the oil pressure sensor, as it is still running fine and oil level is where it should be.

My haunted 1996 Blazer 4.3 acts the same waY every nine months or so. All I need to do is replace the "distributor cap" and rotor and I'm fine for another nine. The unreachable spark plug under the steering column that hasn't been replaced for about an eon and a half could be the culprit as well. Meanwhile, I keep my can of starter spray handy so I don't wind up with a dead battery in the middle of the forest in northern Wisconsin. The "spider injector" and intake manifold exam are next. HOPE NOT.

That unreachable plug is best accessed thru the left front fenderwell with a spark plug socket and swivel with a 12" extension