Over fueled my 2010 hyundai tuscon when fuel nozzle didnt shut off. now when i am tring to fuel nozzle shuts off repeatedly and fuel guage always shows full

SOURCE: Gas pump nozzle shuts off off repeatedly when refilling fuel tank

Try and see if the vent hose from the filler neck to the tank is kinked or plugged, if those are ok there must be a gas tank vent solenoid stuck closed.

SOURCE: Fuel Tank

I have had this problem. For me it's usually when the tank is really empty. I worked at a gas station and at times, I'd have to replace the gas nozzles when they wouldn't kick off correctly.. I suspect the problem is that the gas nozzle is picking up more gasoline fumes that are being displaced in the tank and venting thru the fuel filler opening. The gas nozzle detects enough gasoline vapors with it's sensor to shut-off the nozzle. One can slightly adjust the nozzle in the fuel filler opening (or wait a few additional seconds giving time for the fuel vapors to exit the fuel tank)) and it works great.. I do not believe it is a problem with the Blazer. It's a combination of the gas nozzle and the amount of vapor escaping the filler opening with the displacement of vapor in the gas tank. I've had this happen in my Ford Contour.
I hope this helps others.

SOURCE: Gas pump nozzle shuts off off repeatedly when refilling fuel tank

Replace the filler neck that goes to the tank.

SOURCE: digital fuel guage

yes. the fuel sending unit in the gas tank does need to be replaced

SOURCE: 2001 hyundai sonata 4 cl can't pump fuel into tank @ normal rate

The sending unit in your tank is going bad replace it.