I have a 1987 Ford Ranger XLT 2.3 and the fuel gauge is inaccurate. The fuel sending unit was just replaced and the fuel gauge wont go past an 1/8 of and tank and I'm lost.

 

Welcome to the forum

Google: Ford anti-slosh module

These were a problem as they aged

In 1989 ford change to a different type of sender and gauge

Your 1987 sender should show 73 OHMs empty tank and 10 OHMs with a full tank

Ford used a Yellow/white stripe wire from gauge to sender in tank, if you pull out the instrument cluster you can find this wire and use an OHM meter to test it, then rock the truck to make sure OHMs change as Float goes up and down with the gas sloshing around.