If you're using the old gauge and a replacement sender, that's your issue. The stock gauge is linear and the new replacement senders are non linear and they will work incorrectly. It sucks because it still happens with an autometer gauge
I used an OEM style sender.....when I pulled the old original one it looked the same as what I was putting in.....??? So not sure....but if that is the issue I guess that explains it.....
But wouldnt an "oem style" part be the correct type?
