1992 Ford Ranger Question: My engine oil pressure is fine at low engine speeds, but drops at higher rpms.

The engine in my Ford Ranger is the 2.3L four cylinder engine.

Any dents in oil pan sump? Sounds like a loose pan baffle or pickup tube is damaged past the screen, in the tube itself.
When not submerged in oil it will lose prime so to speak. Then when oil covers the leak again it pumps oil corectly.
2.3 has a fairly long pickup tube! Pan will have to come off to fix. Hook manual test gauge in place of oil sender and see what the actual pressure is first thing. May also be crud in the pan. Dont know your skill level but that is some of the things to check.
Good luck.