1.) Fuel pressure? The continous noise on the fuel rails may be the regulator stuck open and dumping pressure into the return line.
2.) Injectors not firing? A Noid light available from Autozone, is one way to test the injector wiring. I like to use an old injector with compressed air applied to the injector where the fuel rail would normally connect. I hook the whole thing up, apply compressed air to the injector and stick it in a paper cup of soapy water. When the engine cranks with the ignition switch on, if the injector fires, it makes bubbles. Cheap if you have the stuff laying around, and works good too.
There are two 10 pin connectors at the back of the upper manifold, one of them has all 8 injector connections. Pull them apart and check for damage. Clean the connector pins and sockets with electrical contact cleaner or non-inflammable brake parts cleaner (same stuff as electrical cleaner in a bigger can). Scrape the pins with an exacto knife and use a jeweler's screwdriver to scrape the inside of the pins. One of the pins is the +12 volt supply to the injectors. Each injector should ohm out at about 13 ohms +\- 1.5 ohms.
Remember that the computer supplies a ground path for the injectors. The power for the injectors comes through the ECC relay located on top of the computer. They have power to them any time the ignition is on. The computer turns on the ground and completes the circuit, making the injectors fire. Pull an injector wire connector off and look for 12 volts on the red wire when the ignition switch is on. No power, then look for problems with the 10 pin connecter (salt & pepper shakers at the rear of the upper manifold)
