97 xj no start but cranks over

Ok, finally picked up my 97 xj project jeep. This jeep has the 4.0 and AW4. I started it last night and drove it off the trailer. It was running but had to stay on the gas to keep it running. Finally it would just die when I would put it into gear but it would start and run.
Well after a few minutes of trying to get it to move, it would just not start anymore. One thing I noticed is that the fuel guage was not registering at all when it showed 3/4 tank last night. I have also noticed that the fuel pump does not kick on at all now when you turn the key to on and there is no pressure at the fuel rail anymore.

I have checked all the fuses, switched relays around, and checked all the wiring. Everything is fine. I am going to switch the computer on the driver fender to see if that helps. My question is, why would it register fuel on the guage and start up, than the next second not show anything and the fuel pump not working. Any opinions out there are appreciated.

Kim

I fried the computer. I installed a different one and good to go.

Put a voltmeter between the battery terminals--how many volts with the engine off?

Sorry, already started the strip down. Almost everything is disconnected and ripped out in the engine bay. I just wanted to get it started to get it into the garage. To much snow on the ground to just push it around.

Could just be a low voltage issue. Anything below 9 volts and engine management becomes spotty or non-existent.

As starters-solenoids are voltage dumb the engine will keep cranking long after the required voltage to start the engine is long gone.