Been in garage 3 years out of gas. Smells of varnish in tank.suggestions?

 

You could add a couple gallons of gas to your tank and bounce the back of the car up and down and push side to side, then pump out or siphon the fuel out to see how it looks. If it's not perfectly clean, you may need to remove the tank if it doesn't have a drain plug, to flush properly. replace fuel filter and drain old fuel out of lines. replace filter again after a few tanks of fuel. The gunk that maybe in your tank and lines could really raise hell with your fuel injection system. Need to be sure she's clean.

 

+1
Your gas has evaporated leaving nothing but sludge behind. If the car is started with that crap mixed with your gas you will need major repairs once the engine becomes gummed up as well. The tank and lines need to be thoroughly cleaned before thinking about starting the car.