It doesn't have or need a line connected to it. The spider is inside the vacuum chamber.
It could be a vacuum lock. This is the easiest to diagnose. Try replacing your gas cap and see if that helps. If not, it may be a clogged fuel line or fuel injector line or nozzle. You'll have to take it to a mechanic to have this checked out.
If you lower the fuel tank you can.
Not in the vacuum line.
No
On the fuel line going to the carburetor.
It doesn't have a vacuum line attached to the fuel pressure regulator.
Inspect the vacuum line that feeds it. There is a good chance the vacuum line is damaged.
The fuel line is located on the drivers side on the top of the frame.
I cut the line right behind the fuel filter underneath the blazer and installed a high pressure in line fuel pump i got off eBay
Check under vehicle follow the fuel line from tank
Two fuel lines, one supply and one return. The third line is a vent line.
The heater blend door is not run by vacuum. It is run by an electric actuator.