jeex XJ cranks but no start

the other day i was driving downt he road when my 91' XJ laredo 4.0 just stopped while i was driving... pulled over the motor would crank just fine but it wouldnt start.. first guess was fuel pump/ filter.. got a brand new pump and filter still wouldnt fire checked the relay for fuel pump and auto shutdown both were fine changed all plugs/wires dist. cap and rotor still wont fire except if i pour gas directly into the throttle body it will start until that gas burns up so its not getting gas somewhere alone the way but the lines arent clogged i ran a air compressor hose through both send and return line both were clear does the xj have a fuel cutoff switch somewhere or does anyone know what it could be

The crank position sensor tells the computer that the motor is rotating and where the pistons are in there stroke. Could be somehting else, but if the CPS isn´t working the injectors don´t cycle and the ignition won´t fire. Though there are other possibilities. The MAP being unplugged, seems to do the same on my Renix.
Have you checked to see what codes are stored in your ECU?
http://www.jedi.com/obiwan/jeep/dtc.html
Does the fuel rail have any pressure? Can you hear the pump working, when you first turn the key on. Does your XJ have an anti theft system.

my 88 did the exact same thing it was the CPS
shorted or something so the computer never knew the engine was rotating so no fuel or spark

wierd that yours will start when you pour gas in though. so its gotta be getting spark.

tap the bottom of your tank with a rubber mallet and see if that wakes up the fuel pump..

Just check the fuel pressure at the rail.