I'm currently looking to buy a 90 Vert. I was wondering if anyone could tell me what the normal oil pressure is on one. Also, the pressure increases to about 38 when accelerating and holds steady through the higher rpm range, but when decelerating it drops back down to about 30. Is this normal? Sorry about the newb question, but any info would be greatly appreciated... thanks

 

http://www.rx7.voodoobox.net/infofaq/bguide/bguide.html

that should help. it was my rough checklist when i bought my fc haha.

 

Keeping in mind that the car is approaching 20 years old, it's not surprising that the oil pressure sending unit might be getting tired and giving wonky readings.

The best thing to do (although also the most involved) would be to connect a mechanical pressure gauge into the stock sending unit's location and see how it correlates to your gauge's readings.
Next easiest would be an aftermarket pressure gauge.

Or you could just go to Mazda and get a new sending unit.

My oil pressure (on a 91 NA with an unknown pedigree engine and middling compression) runs between 15psi at idle and 50-60psi at WOT.