My '92 Miata with about 90K, has been pegging the oil pressure gauge at the
90 psi mark during acceleration. Thinking it was the gauge or sending unit, I took it to my mechanix. He said the both were fine and the oil pressure was actually in the 70-90 psi range at 2500-3000 rpm. He said the oil relief valve in the oil pump has failed and a new pump is required at huge $$$. A big labor job...Is this possible?? Any way to find out without the big $$? All input is welcome. Thoughts. Thanks!