I have a 88 rx7 13b and i am curious if someone could tell me what is going on with my car when I start it the idle goes up and down also lately i've noticed that when i start it my oil pressure gauge does not move until i am driving about half of a block and then it reads about 30 psi other times it reads 60psi and its constantly fluctuating i've checked my oil level is o.k is it my oil sending unit or maybe the sensor please some one help

 

had the same problem with mine. got an aftermarket gauge and found out i actually have oil pressure. the stock gauge never reads right might be a ground or the sending unit but in either case i would just get a mechanical gauge and have a reliable reading.

 

Not true...
It does work fairly well when everything is in working order.
Most likely the contacts to the oil pressure sensor is dirty and / or covered with oil, since the oil filter sits right above it; changing oil can drip oil down onto the sensor, which will screw up the signal / readings.
...or, the sensor just needs to be replaced.
The oil pressure sensor has been known to get flaky - pretty common problem.


-Ted