1997 subaru 2.2L eng. Only 4.25 volt at the fuel pump connector

Check fuses first. With a volt meter check for power to the fuel pump relay and thru the relay. Check for power at the fuel pump connector in the trunk. If you have power to the pump replace the pump.

Sounds like a bad connection between the two points.
It may be easier to run a new wire than to tear the harness and connectors apart.

SOUND LIKE FUEL PUMP FAILING. REPLACE FUEL PUMP RELAY CHANGE FUEL FILTER.CHECK FUEL PUMP PRESSURE SHOULD BE 34 - 38 PSI.

You should have an access panel under rear seat or in cargo area. on passenger side. here is a replacement procedure

Hope this helps, it it does please leave feedback and vote Thank You and Good Luck

1. Release fuel pressure.

1. Disconnect fuel delivery hose (1) and return hose (2).
2. Disconnect jet pump hose (3).

1. Remove nuts which install fuel pump assembly on to fuel tank.

1. Take off fuel pump from fuel tank .

INSPECTION



Connect lead harness to connector terminal of fuel pump, and apply battery power supply to check whether the pump operates.

WARNING:

• Wipe off the fuel completely.
• Keep Battery as far apart from fuel pump as possible.
• Be sure to turn the battery supply "on" and "off" on the battery side.
• Do not run fuel pump for a long time under non-load condition .

INSTALLATION
Installation is in the reverse order of removal. Do the following:

1. Always use new gaskets.
2. Ensure sealing portion is free from fuel or foreign particles before installation.

1. Tighten nuts in numerical sequence shown to specified torque.

Tightening Torque: 4.4 ±1.5 N.m (3.3 ±1.1 ft-lb)

The fuel pump is located behind the rear seat on the passenger side. Remove the upholstery cover to expose the metal oval cover which will expose the fuel pump. D/C the neg terminal and the electrical connector. Remove the nuts to release the fuel pump from the tank. Only now you can release the fuel hoses. Reverse the procedure to reinstall the new fuel pump.

Try replacing the fuel pump relay

Disconnect the wiring connector of the fuel
pump.

Crank the engine for more than five seconds.
If the engine starts, let the engine run until it
stops.

After turning IG switch OFF, connect the wiring
connector of the fuel pump.

Disconnect ground cable from battery.
2) Loosen the screw of the hose clamp and pull
off the hose from the filter.
3) Remove the filter from the holder.
4) Replace fuel filter with a new one

10psi is, as I'm sure you know, about 48psi short of what you need to get it running. Did you verify you're getting a full 12 volts at the fuel pump connector? Check the ground wire also, ohm it out to chassis ground, shouldn't be more then a few ohms. Verify it's making a good connection and the terminals are clean and tight. High resistance in the wiring or a connector in the circuit could cause the fuel pump to not output the right amount of pressure.
Did you replace the fuel pump with an aftermarket unit or an oem part?

Ign switch

nope. no suggestions. you hvave a dead fuel pump! Mine went exactly the same way.