So I have a 1990 ford ranger 2.9l, just replaced fuel pump due to float filling with gas and my fuel gauge not working, but now it reads about a 1/4 off, showing I have more gas in it.
Anyone have any ideas on what's going on?

 

1989 and up Fords would use the 16-158 Ohms sender, 16ohms empty and 158ohms full
There are different styles of senders available.

If you had a corroded connector it might create higher resistance(higher ohms) so it is showing higher fuel level than it should.
A corroded ground could do the same thing.

Should be a 4 wire connector for fuel tank
Yellow/white wire is the senders wire to the gauge
Orange wire is the senders ground

Also the chance that the float arm got bent on installation.

 

RonD beat me to the punch. I'm thinking that the last thing you did relating to the fuel guage issue is suspect. I'm assuming you had to remove the entire fuel pump/fuel sending unit from the gas tank (you either dropped the tank or removed the bed) to replace the fuel pump...You may haver to do it again to see if the float arm got tweaked during re-installation, or related got damaged.