Starts with starting fluid, but will not start with fuel pump manually turned on?

This can be because of bad ignition module even though is has spark or I have seen a bad MAP sensor not tell the computer the engine has vacuum which will not turn the fuel pumps on. Have you run the codes to see if any are stored?

https://www.2carpros.com/articles/ford-lincoln-mercury-obd1-1995-and-earlier-diagnostic-trouble-code-definition-and-retrieval

Here is the locations of the map sensor which I would try swapping out. Check out the images (below). Please let us know what happens.

No codes are pulling up, I've replaced the fuel filter and pressure regulator as well, and Noid test confirmed I've got injector pulse. I'm having trouble understanding why it's not starting even with the fuel pump manually jumped at the relay though.

That is a good sign, did you check the inertia switch? Did you check fuse O in the under-hood fuse panel? Here are the wiring diagrams so you can see how the fuel system works. Check out the images (below). Please let us know what happens.

Yes, inertia switch, tank selection switch, relay and fuse are all working correctly, my fuel pressure Guage isn't working properly though so I can't tell exactly how much pressure there is when the pump is forced on, it shows 0 but the test port sprays out at a decent rate when valve core is depressed.

The fuel pressure gauge shows 0? this would be the problem then.

It's a faulty gauge, it isn't depressing the core of the test port, I can assure that there is much more than 0 PSI.

Did you swap out or check the vacuum line to the MAP sensor?

Vacuum line is fine, replaced MAP, still won't start.

hmm, so no codes, the engine has spark, and fuel pressure and all the fuses are good. let check the power and ground for the PCM and if okay I would replace the ignition module and then the PCM with a rebuilt unit. Please use this guide below to help check the power and ground. Please use the wiring diagrams above.

https://www.2carpros.com/articles/how-to-check-wiring

Please go over this guide and get back to us.

I may have found the issue, I found a mouse nest under the intake, there's a chance the injector wires for half the engine have been chewed up, I will check and update after I get the intake removed.

Good find! I can't tell you how many times rodents cause these kinds of problems.

No damage to any of the wires, however I did find that almost all of the injectors were completely clogged, flushed out the fuel rails and ordered new ones. will update if it works.

Yep, bad tanks of fuel can clog the fuel injectors, have a good weekend, happy wrenching!