Puzzled,
It first started out as intermittent starts. Then wouldn’t start. New fuel filter, new ignition coil, new spark plugs, new fuel regulator, new MAF, new idle control, new crank sensor. Finally got it to start but rough start. Tried feathering the accelerator but couldn’t get RPMs up. Push down on the accelerator and dies. Have spark and fuel to the schrader valve.
Now I’m back to no start.

 

See if the engine grounds are still there on your 31MY old truck.

 

The ground from the back of the motor to the body is there. Cleaned and shined it up. The battery cable looks like it in good working condition. Have a ground from the battery to the body. I bought the Ranger in 1996. Could it be the alternator or solenoid?

 

I do not know but I'd think not.
Maybe check your ECU and ANY related connections (electric multi-plugs) for corrosion.
The large multis which connect at the firewall are not immune from water incursion.

Does this era Ranger have a TPS which can send bad info? Can't bad ignition switches cause vexing probs?

Bro, I'm just shooting in the dark.

 

I have the same year and engine/transmission. I was having similar issues. I would recommend opening the computer and checking the circuit board and see if the capacitors have leaked and ate away the traces on the circuit board.