My 96 has been reading about 100 psi on the oil pressure gauge on the dash since I bought the car, about three weeks ago. I changed the oil and used 10/30 and it'* still the same. Does not matter how warm or cold out side, today it was 68, a week ago it was 17. It also does not matter if the car is cold or hot. I read an old post on this issue and some people said to try and replace the oil pressure relief. This was on a 91. Would you recomend I try the same thing, and if so is it the same set up as the diagram shows for the 91?

sounds like it could be the oil pressure sending unit, not unheard of failure at all.

my question for you is after the engine is warmed, does the gauge move at all when going from idle rmp'* to acceleration rpm'*? there should be clear movement in the needle when you do this.

does the gauge needle go to a "parked" position when the engine is off?

Pretty much any time it goes high, it'* the sender.

It does not move much at all between idleing and reving. When the car is off it drops all the way to 0 on the left.

third vote.

pressure sender.

common failure, and pretty easy to replace.