fuel gauge reading wrong

[JGSA]

I'm no expert, but I'm having the same type of problem with my CSX. To the best of by knowledge It is a Fuel Safe racing cell with a fuel sending unit manufactured by Centroid. The unit does not have a conventional "float" but works on the basis of measuring capacitance of the fuel within the tube. There are some excellent instuctions on calibration on thier website http://www.centroidproducts.com/fsafe.htm. The kicker is that the length of the sensor tube within the tank does not run from top to bottom, but enters somewhere near the center of the sidewall of tank. Therefore once calibrated, the gauge indicates the tank is full while the sensor is fully immersed. The tank may be close to half empty when the sensor just begins to become exposed and change the reading on the gauge from the full mark. How accurate the gauge reads from this jump from a "full" tank to the actual level is beyond me at this point. I calibrated the sending unit as per instructions, both empty and full. When I begain to fill the tank a second time, it read 1/4 tank with only 1 1/2 gallons of fuel in a 23 gallon tank. Go figure. IMHO the placement of the sensor, and the shape of the tank prevent an accurate reading. For now I'm keeping an eye on the gauge, and keeping an extra 2 gallons in my trunk until I figure this out.