I too am wrestling with a fuel pump, albeit the one on my old f150. Im not really familier with the jeep system. But on my old ford, the pump comes on, when you turn the key to build pressure, but it stays on and the truck wont start. However, the pump shows 50lbs at the fuel rail.
I know this is a XJ forum, but I thought somebody might have some generaic suggestions, on things I havent looked at. Things I have checked: All relays(ECM, Fuel Pump) Engine coolant sensor, Air Temp sensor, MAP sensor, spark at spark plug, also checked the grounds to the computer(Theres three of them, 2 of them showed >5ohms and the one going to the fuel pump/rear lighting showed 11ohms). Everything I read says that ford ECM's never die, but seems to me like it is the culprit. Anyway, thank you in advance!