Will not start, possible fuel pump issue

Even though you have fuel at the rail doesn't mean it is making it to the cylinders where it needs to be. There is something that would need to be clarified which is, when you spray the starter fluid and it runs poorly but starts, does it continue to run when you stop spraying starter fluid? If it does not and the only way to keep it running is to continue to spray starter fluid then this is normal. We don't want to have it continue to run on starter fluid, just see if it starts the engine.

If it does start and run then I suspect you have a weak fuel pump. It continues to run with the key on because it is not building the proper amount of pressure but it is building just enough to keep it running (poorly) after you give it a little help with the starter fluid. It's almost like you are just priming the system on a carburetor vehicle.

I know you said you don't have tools but we need to confirm this by testing fuel pressure. If you have access to a parts store, most of them have tool rental programs and you can get this and hook it up and prove this out.

You should have about 55 PSI when you just turn the key on. I would guess you have around 25-35 PSI. Everything you are stating points to this.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Please come back with questions. Thanks