Another problem I'm having with my 85 4Runner is low oil pressure indicated on the factory SR5 gauge.

No oil lights or anything like that, just a low and sluggish reading on the gauge. Pressure is just barely within operating range (actually between the first and second lowest lines on the gauge), but it takes a 30 seconds or more for the needle to raise up to this point. Revving the motor helps it raise up more quickly. I am thinking its either a bad gauge, clogged oil pump screen, or bad oil pump.

I fired up my 86 parts 4Runner and the oil pressure gauge immediately read a higher pressure, so I know its not a consistant low gauge reading.

Any ideas on what steps I should take next? Thanks.