Sounds like the fuel solenoid isnt operating...the plug you installed may have closed off the jet..
Put 12 pos to the solenoid terminal...and ground the side of it...it should pull in (click) when voltage is applied..
Crack loose the fuelcap to insure that its no clogged...causing the fuel to stop flowing ...
Backflow the fuel line to the fuel pump...blow air through the hose back into the tank...might have a fuelline obstruction or a kink in the hose...
Backflow the fuelhose again...this time with the fuelcap tight...just a little air...check your fuelflow..should be good..
If You Have All The Answers...Except The One You Need...You're Not Trying Hard Enough...
Do The Work