I am having the same problem with the same year, make and model.
I have replaced the ECM (ECU, Computer, or whatever else it is referred to as).
Completely rewired the engine compartment so it no longer crosses under the upper intake, installed a remote TFI on a heat sink from a 94 Taurus, (I really do recommend this mod).
New cap & rotor (brass contacts from NAPA)
Replaced all injectors
Cleaned the fuel tank and replaced both pumps
Checked compression (242,000 miles--135# to 145#)
I have just about run outta things to try. But have a lotta money in it now, so will keep at it.
I am going to recommend a web site I frequent that has a lot of info about Rangers/Bronco II's. The Ranger Station - Your Ultimate Ranger Resource
Keep us posted as to what you find.
You might also want to see about pulling the codes, if any come up.