1986 Jeep Comanche Custom 4-Cylinder, 2.5 Liter, 4-WD, Gas. Why the Fuel Gauge stays put FULL even when I know its not (gauge never move)? I have a Chilton's Book Pat No. 8143 and can't find or figure out where the fuel sensor is. Does it have a Fuel Sensor or is it the TBI FUEL PUMP inside the fuel tank operates the Fuel Gauge?