Get some fuel pressures and do a leak down test on the fuel system. The leak down test will tell you if you have a stuck injector, bad FPR or a bad check valve. If you have no or very little leak down, you're good all around.
You need a helper for the following tests, though.
You'll need a hemostat or vice grips.
Get the Jeep running and have your helper turn off the Jeep, right as they do that clamp the feed line from the tank to the manifold, you'll have ot do this under the Jeep between the tank and fuel filter. If you don't have leak down, the check valve is probably bad in the fuel pump assy. You can replace the pump or install an external check valve inline with the feed line.
Next, assuming the last test still resulted in a quick leak down, do the same procedure but clamp the return line this time. If you still have leak down, you've narrowed it down to one or more of the injectors or a bad FPR.