Welcome to TRS
Nothing comes to mind right off
But you could find out if it was spark or fuel causing the no start using 50/50 test
After engine is warmed up and doesn't start
Pop the hood
pull off the power brake booster's vacuum hose, from the booster end, hold it up
Spray Quick Start(ether) or gasoline into the hose so it goes into the intake
Put hose back on and try to start engine
If it starts and dies fuel system is the problem
If it doesn't fire then spark is the problem
50/50
1994 4.0l used EDIS-6 module for spark it was usually located on the front side of the Rad support to keep it cool, i.e. out of engine bay and in cooler air.
Where is yours located?
You don't mention poor MPG which would be a sign of leaking injector or FPR(fuel pressure regulator)
This can cause Flooded Engine issue on warm start.
CKP(crank position) sensor is the main sensor for the system, only sensor that can cause a no start, but these rarely fail, not never, just rarely
CKP sensor generates its own AC voltage as crank spins next to it, it isn't a high voltage, so can be effected by heated wires.
CKP is located at about 10:00 on the front of the engine next to crank pulley, its wires run up the front of the engine around water pump and into the main harness on lower intake.
Have a look at that section of wire, make sure it hasn't been damaged and insulation is still intact
There was a member here that had similar issue with 2.9l using TFI ignition, so not related at all to your type of system, but...........
He had an interesting approach to find the problem............ICE
Used a bag of ice to cool down TFI module or coil or ?? to see if engine would restart faster in one of the components was cooled down