oil pressuer Gauge problem

[wildcar]

My girlfriend has 93 two door sport XJ and the oil pressure gauge dosen't work. most of the time it just sits at or around 3/4 pressuer and dosen't move. Is the gauge bad or the sensor and how can I fix it, and where is the sensor on the motor?

[Matthew Currie]

It's probably the sensor, but there's an easy way to test. The sensor is on the oil filter adapter. You'll see a little gadget with a wire plugged in, just above the filter, placed in just about the right place to break when you remove the filter. That's the sensor. On a 93, if the sensor is unplugged, it should "pin" the gauge at maximum. So unplug the sensor (note that it's one of those plugs with a little latch on it, and don't break the latch). The turn the ignition on. If your gauge goes to max, it's working. If the gauge stays at 3/4 even when unplugged, the gauge itself is bad.