Well RIP, I finally solved my problem. See below
Expert: Dennis W
Subject: Ford Ranger Engine
Question [Asked by someone else]
My Ford Ranger 4.0L automatic 36000 miles will not rev over 3200 RPM. Engine operates normally up to 3200 RPM then surges approx 100-200 RPM at 1-2 second cycles with a distinct rocking (out of balance), this quickens with increased accelerator pressure. The problem occurs without a load (revving in neutral)- the check engine light is not on.
This is normal if you are revving the engine in park or neutral, the PCM has a rev limiter to prevent engine damage. If the symptom occurs while driving you might have a problem with the MAF sensor or fuel pressure. Check for codes BEFORE making or attempting any repairs.
In my original question I wrote: "I'm wondering if there is a built-in governor so high RPM idling is prevented or if I have a real problem ???"
Then later I wrote: "The problem is the motor stalls/misses when it reaches 3,000 RPM's and will not turn any faster."
I could not have made this any clearer. It does not occur while driving and the idle fluctuation only happened the one time and never since. Obviously, I have no need for any parts or any repairs. Perhaps if this comes up again, you will know how to respond correctly without recommending unnecessary parts or unneeded service repair.