1986 FZX700 (Fazer) Fuel Delivery Troubles

Hello All, I'm looking for some advice on my Fazer 700. I purchased it around a year ago (it was sitting for about 20 years) and have been slowly going through everything that's needed attention. I've reached the point where I'm ready to fire it up to see how it runs but I can seem to get the bike to run for more than a few minutes. I believe my issue resides within the fuel pump controller circuitry or fuel pump itself as I've tested a bunch of different scenarios to rule things out.

When I go to turn the ignition on with the handlebar fuel switch set to ON, I'm supposed to hear the fuel pump run for a few seconds (~5 sec), but I only hear it kick on for a split second if it even does at all. I have the gas tank nearly full, the fuel sender was just replaced, and a new fuel filter was installed to rule all of those out. If I switched the handlebar fuel switch to RES, I would hear the pump kick on for about ~5 seconds and occasionally gas would pour out from the carbs (I think the solenoid shutoff must not be working properly). I would then be able to start the engine and run for a few minutes before it would die out from lack of fuel being delivered. I began to wonder if it was a carb issue so I gravity fed the carbs and it had no issues running and idling for an extended period of time. I swapped the original fuel pump with an aftermarket one I purchased, and the issue seems to have gotten worse where now I can't rarely ever hear the fuel pump turn on when the ignition is switched on. I've done some voltage measurements on the fuel pump controller harness and have noticed that the input (blue and black wire) running to the fuel pump will be high (~9-12V) for a few seconds but that doesn't coincide when the fuel pump is on. Sometimes the signal will be high, and the pump will be off (possibly from the solenoid shutting the pump off??) I ordered another fuel pump controller (used) out of desperation but that made no difference.

I'm hoping someone can shed some light on my situation. I have no idea where to go from here.

 

If it's like my FZ750 then there's also a signifcant in-line fuel filter. I'd be looking at changing that too.

 

I thought that too at one point, so I replaced the filter twice and ruled it out after I had it running when I gravity fed it. It seems to be an electrical issue, but I don't have any information on how the fuel pump controller operates so I can't test the logic.