1g Gas Gauge Reading incorrectly

[Coder24]

I installed white face gauges in my 91 Tsi and now my gas gauge is off. I went to fire up the car for the first time since the rebuild and I thought i had more gas than i did because the gauge and it fires up but then it wouldnt. I thought it was other shit but i shook the tank and put more gas in and it was empty. now it reads a quarter when i put 2 gallons in(16 gallon tank...its FWD) It was reading that i had about 2 gallons. How do I fix this? so its correct

 

[Backinajiffy12]

Search for the forum Gas Gauge no worky that helped me out i would tell you what it is but i cant remember the name of the peice you need to straiten on your sendding unit