Tempature Sensor/Dash Gauge

My factory Temp. gauge on my '93 XJ Sport doesn't work. I have replaced the temp.sensor at the rear of the head (not the one at the thormostat housing for the ECM reading). In fact, I thought maybe the first new one from Advance Auto was bad because I ran a "jumper wire" from the wire harness conection (that conects to the temp. sensor) to a ground (the engine ground wire connected to the firewall). The temp gauge in the instrument panel registered. This should mean the gauge itself works. However, when I screwed the temp sensor into the head..I waited for the engine to heat up and the thermosat to open, but still no reading at the gauge on the dash. Any ideas'?!?!?!

PatriotJeep

Change the gauge.

Hey, i'm kinda having the same problem with mine. I've got an 87 4.0 laredo. You engine might have a bubble of air stuck at the back of the cyl head. to fix ( you really have to go off-road for this), park face-down on a really steep hill in 4WD, and bleed the air from the block by removing the Temp sensor and waiting for fresh coolant to flow out. drive the jeep around for a day or two and repaet.