The only thing that comes on my mind right now is that You hook up a gauge to a schrader port which is after the filter, right by the spider. Maybe the pumps don't die but there's something in between the pump and the schrader that blocks the flow so the pressure drops? Have You tried testing the output pressure of the pump at the bench with a battery connected directly to a terminals?
P.S. I have an idea to tap the fuel pressure senor via schrader to get the live fuel pressure reading on my dash. I'd have to dig through the sensor offers, as vast part of them are for diesel engines that operate on much higher pressure range.

 

Mike, I also test pressure at the fuel filter fitting. At that point, the only thing between the pump and guage is about five feet of fuel line.

Edit to add: testing at the filter fitting, the pump goes directly into the guage. It's completely isolated from the whole rest of the fuel system at that point.

I'm replacing the both the feed and return line from the filter back, mostly so I can just get new flex lines. The return at the pump was jacked up from previous owners, so it needed to be fixed, regardless.

 

So, update time.

New ac declo pump and strainer. New fuel lines from the filter back, new filter, and I washed the tank out at the car wash.

Inside of the tank looks really good, at least what I can see. Shiny metal, no rust whatsoever.

It's back together now, pressure is good, 60 psi. This ac Delco pump holds pressure much better than the delphis did. It held over 50 psi for about 7 minutes. I know the spec is ten minutes, imbut the delphis would plummet below 50 almost instantly, so it's still an improvement.

Going to take it on an extended test drive later on. So keep your fingers crossed

 

Gosh, You scarred me I've seen Your thread bumped to top and my first thought was "another pump bites the dust". Good luck! I am hoping this one will be for good.

 

Keep us posted.

George

 

21 miles so far, so good. It's already doubled the life of the previous pump! Lol.

I'm supposed to be going to an off road park next Saturday with some of my friends. Hopefully it'll make it there and back.

I sure don't want to have to ride shotgun on someone else's ride, and be on strap duty!

 

Do you think it was the previous fuel pumps then? They just didn't have the quality to keep the pressure up? I'd say if it handles the off roading you've got no more worries.

 

Still really too early to tell. Only have 76 miles on this pump. But it's already lasted longer than the last one. But the only difference I can see is the inlet being bigger on the ac Delcos.

I'll drive it more this coming week and keep this thread updated with how it turns out.

 

Could it be possible the ones You had were not genuine but a fake?

 

I got them from advance auto, a large chain store. Wouldn't think they would be fakes.