Follow Dans advice for starters.But unless a fuel stabiliser was added to the gas tank,the gas has gone stale and started leaving varnish deposits.Depending on the fuel,what addatives are in it.Summer gas or winter gas for example.Gasoline starts going stale somewhere between one and two years.If the tank is more then 1/4 full,I would recomend draining the tank.If it's 1/4 or less,fill the tank with fresh fuel before you start it up.And whether you drain the old fuel or not.I would recomend adding a fuel system cleaner to you'r tank right away to disolve those varnish deposits.I personally like Sea Foam brand.I've seen it do a better cleaning job then any other brands I've tried.But who knows,maybe one of the brands I haven't tried is even better?Once you've got it running,keep an eye out for oil leaks during the first week or so.Seals dry out and crack from sitting sometimes.And if the car sat on the ground without being moved at all for four years,the tires might need to be replaced.If they act like their out of balance when you get it on the road.Then the tires have developed a flat spot.Sometimes they'll smoth out again within twenty miles or so.If not,replace them.