I thought most diesels were supposed to be around 60 psi maximum at 2500rpm. That gauge sounds suspect to me
The psi at idle is almost irrelevant ,it just needs some. It is at highway rpm where you need the psi to be within spec.
I would try another gauge and do the tests outlined in the FSM.
FYI ,the oil pressure test on a Toyota diesel is done on a warm engine at about 2500 where you keep it at that speed for 2 mins. I forget the exact specs but it is approx 34 psi min and it should maintain the psi for the 2 mins without falling off.
The psi at idle is almost irrelevant ,it just needs some. It is at highway rpm where you need the psi to be within spec.
I would try another gauge and do the tests outlined in the FSM.
FYI ,the oil pressure test on a Toyota diesel is done on a warm engine at about 2500 where you keep it at that speed for 2 mins. I forget the exact specs but it is approx 34 psi min and it should maintain the psi for the 2 mins without falling off.