Fuel level gauge becoming delayed
This just started the 2 days ago. I have an 03 mitsubishi galant. I got off work and was getting ready to head home when i realized my fuel gauge was showing below E. I put gas in it a few days prior but just figured maybe i drove around more than i realized, so I went to the gas station and filled up. But to my surprise, only about 4 gallons would pump. I started the car and looked back at the gauge before i left to see what it showed, but it was now moving up to the full mark. I didnt think much off it, and just figured id keep an eye ob it to see what happens. It didnt happen again till today, coming home from school. It was again below E, but knowing that i just filled it up, i decided to just drive it and see what happens. Well, after about maybe 3 or 4 miles, the gauge started moving up and stopped at just a hair below the full mark. Im really curious as to what is going on. I work at a dealership as a tech apprentice for my schooling, but Ive never seen or heard of this before.
Any help or pushes in the right direction would be much appreciated.