1997 Chevrolet Blazer - consequences from sugar in the fuel tank

Ex girlfriend put sugar dissolved in water and karo syrup in my 97 4.3 vortec blazer, unaware I drive it but find that I can’t get gas to enter into the tank at the station, karo syrup had stopped up the fill tube. She confessed and I started using my Tahoe and parked the blazer for six months or so, it ran fine when I parked it. The other day I decided to try to start it and it would barely run. I’ve cleaned tank, changed filter, still won’t run right, I know I should have fixed it immediately and now wondering if letting it sit up so long is the problem or am I looking at replacing the damn injection system. Help. I have more info but I’ll keep it short til an expert weighs in

The syrup is going to gum up the fuel pump and possibly the injectors. First check the fuel pressure to see if the pump is operating properly.

You may need to flush the entire fuel line and fuel rail.
If you have good flow out of each port at the fuel rail, then you may need new injectors.