I installed a holley 70mm TB on my 93 GT and I tried to set the TPS to between .8 and 1.0 but I couldn't get anything but .56. I even tried drilling the holes out bigger and try to turn the sensor but still it was only .56 and that is it. it never changed. What is the problem? BTW it seems to run fine but would it run better with it set correctly? Thanks.