2002 Plymouth Voyager Dirt in fuel lines

You can try pushing on the schrader valve, located on the fuel rail to see if you have fuel getting to the injector but that doesnt tell you the pressure or volume. Without that it can just give you a rough idea if you have fuel or not. Thats about as far as that will get. Same thing you can dump gas in throttle body and see if it sputters up or not.

The vehicle if ran very low on gas the pump can overheat causing the pump to burn up and now the pump isnt suppling the proper pressure. Dont worry if your thinking you have air in the lines as its a gasoline vehicle. Cranking it enough will cause the air to be purged out.