Flashing CEL means misfire is occurring, this can damage Cat Converters so it Flashes.
Codes will tell you which cylinder(s) were misfiring.
I would hit a wrecking yard and pick up a couple of coils, Ford V8's used same dual coil setup.
Also the ICM(ignition control module) has been a problem as they get older.
It is located on the front of the intake manifold.
It can be tested, read here: Part 1 -How to Test the Ignition Module and Crank Sensor (2.3L Ranger, Mustang, B2300)
Some auto parts stores have testers for ICMs, they test it for free.
Most auto parts stores won't be able to read your OBD I(1) codes, they only have readers for OBD II(2) 1996 and up vehicles.
But you can read them yourself: Ford Ranger - Testing EEC-IV Equipped Engines