What is the Gas pressure

If your talking about fuel tank pressure sensor, it's in the gas tank. My info says you need to drop the gas tank. You would need to drain gas tank before you drop it. Take electrical connectors loose. Take fuel lines loose. Make sure no pressure on the system before taking any fuel lines loose. So on and so on.

A ruptured diaphragm in the fuel pressure regulator will let extra gas enter the engine through the vacuum line to the regulator. Pull off the regulator vacuum line. Any evidence of gas? Let the engine idle a couple of minutes with the vacuum line off. If any gas starts coming out of the vacuum line nipple on the regulator, then that was the problem. Replace the fuel pressure regulator.

Could be a "fuel pump relay" or ford equivalent that converts ECU fuel output demand signal to power to the fuel pump. To test jump direct positive to fuel pump and see if you get pressure at the rail. If you get pressure, that may be part of the problem. If not enough pressure (but measure) you may have a fuel pressure regulator or ford equivalent issue.

Well, you need a quick tutorial on your fuel system. Now to find a leak, stop trying to start the engine. You are only adding electrical charge to an already dangerous situation. Now stop and think this through. Modern fuel injection requires fuel under high pressure to operate. The injectors are immersed in this pressurized gas, as are the lines leading to them from the fuel tank's fuel supply line. So just by turning the key to ON, not start, you have initiated the process to start the engine, and that means the pump has operated for 2 seconds to put the fuel system under high pressure.

Now if you follow the fuel supply line (from the gas tank) to the engine connection, start here to find a leak. It is now under high pressure from here to the injectors on the engine- one for each cylinder-it should be dripping with gas somewhere. You could even turn the key to off after the pump has ran for 2 seconds. The fuel system is designed to hold pressure in the system for about 10 to 15 minutes, before slowly bleeding off. Enough time to search for a gas leak. A couple of other things associated with the system: there will be also a fuel return line from the injector rail, it goes back into the gas tank. both the supply line and the return line often run alongside each other. There is also a fuel pressure regulator, immersed in the fuel rail, a seal on that may have started leaking. If an air breather housing, or some cover prevents your seeing the fuel system entirely, then set it aside. You should be able to find the leak. Just be careful, have lots of rags handy, happy hands are learning hands.

Have you checked the fuel filter? I would pull the fuel line apart before the filter to see if the pump is putting gas into the line. With key on, the pump should run for 2 seconds to pressurize the lines and fuel rail. And when the engine is cranking over, the pump should be running constant and putting gas into the line. If gas shoots out, possibly the filter is clogged or the fuel pressure regulator on the fuel rail is defective. If no gas comes out, possibly the pump filter sock is clogged or the pump is defective.
Very unusual for the pump to run and have NO fuel pressure.

First of all, the new fuel pump may be bad. disconnect line at fuel filter where it goes through filter. and see if fuel flows, or have someone to put hand flat on bottom of tank and try to start car. if fuel pump is working you will feel a vibration on tank. if it does not work, check the fuel pump fuse in fuse box before you exchange it.and or the fuel pump relay! when car is running it runs constantly, when you simply turn key to on position, it runs for about 3 seconds(until fuel pressure in line comes up. and then cycles off.

Use compression barb fittings on the pressure side with fuel injection line NOT REGULAR FUEL HOSE THE REGULAR HOSE WONT HOLD UP TO THE PRESSURE. The return line can be regular fuel line because of the low pressure.

Use a gage and check proper fuel pressure, with TBI, around 9--13 psi. There probably isn't a Schrader valve, to check fuel pressure tee into supply fuel line. Be aware of possible fuel pressure when taking fuel lines loose.

Some how you have the pressure and return fuel lines backwards. Double check your repair,I am thinking you cut atleast 2 lines for the repair. Just reverse them.

It sounds like the return fuel line is leaking. There are two fuel line and one is the high pressure line which goes to the fuel pressure regulator then to the fuel rails. There is then a return line from the fuel rail to the gas tank.
With the amount of fuel leak, it's going to be the return line since it's not that bad compared to the high pressure side. Follow the fuel lines from the drivers side around the steering shaft to the engine. The high side and low side (return) run side by side and you should see it leaking when the engine is running.
Good luck and hope this helps.