Need help troubleshooting fuel system

88 xj renix I6 auto trans

The jeep had been just dying after it was driven around for about 20 minutes. We noticed the fuel pump was screaming at idle, humming really loud so we changed it thinking it maybe was locking up. New fuel pump in and it wont start at all now. we can hear the fuel pump running with the key turned to on, not trying to start it just powered on. The fuel is flowing freely up to the schraeder (?) valve. Just looking for some input on what to check next. Hooking up the old fuel pump right now to see if maybe we got a faulty unit. Any help would be greatly appreciated.

Rather than checking flow, put a pressure gauge on the Schrader valve.

I would check pressure at the fuel rail while driving it if possible. Run your gauge hose out the edge of the hood and stick it under the windshield wiper so you can see it from inside the car. Drive it til the problem happens. If the gauge shows in spec while the problem occur, check elsewhere.

well thats the problem. we cant get it running now. Could it be electricla like a sensor or something. would the CPS just shit out like that?

If it won't run at all now, verify if its fuel or spark. If you don't have the tools to do that, just use some starting fluid. If its a fuel issue, then you need to check pressure. No pressure? then you need to check voltage to the pump. Voltage at pump, ground good at pump, and no pressure means a bad pump. If there is no voltage at the pump then start checking the related fuses and relays.