My 1990 4x4 pickup's 3VZ-E 3.0 L (2958 cc) engine suddenly began to miss fire.
By the end of the trip it was running on 4 cylinders.

I isolated the miss fire to cylinders 3 and 4, by removing each spark plug lead.
All cylinders have strong spark.

I changed the spark plugs, and used a heavy dose of injector clean with no improvement.
A compression test has 150lb in each cylinder.

Next I pulled off the top end (intake). All injectors are working and there is no resistance in the injector solenoid wires. (no broken wires)

Has anyone ever had a similar problem?

 

Oh yes, the rotor, cap and leads are all new within six months.
I do not have a official Toyota service manual, have no idea of the wiring schematics and know little about the computer that reads and controls sensors, ignition or injectors.