Don't panic until you have fresh gas in it, either -- old dead gas
won't light with a match, let alone burn properly in the cylinder.
Drain what's in the tank, put in 5 gal or so of fresh gas and a bottle
of Techron or RedLine and jumper the fuel pump relay for a couple
hours, then bleed the injector lines. This will get the varnish and
goo out of the fuel distributor (hopefully) and may fix it up.
If not, the internal diaphram on the fuel distributor tends to pinhole
on extended sitting, and there is no fix short of replacing the fuel
distributor.
Peter