A car has not been started for over 2 years. No fuel stabilizer was added to the tank. According to some sources it's best to drain the gas and put in a fresh tank before starting it, because the gas will have gone bad and can damage the fuel injectors or other parts of the engine. This seemed quite reasonable to me, but two different dealerships have said that this step is unnecessary. Is this bad advice from the dealerships?
If they say it is unnecessary, I'd put them in the complete idiot category. Will the car run? Most probably, but it has a large propensity to cause issues down the road.
With that said, there are some caveats we could talk about.
Was the car prepped to stand that long?
- If the car was filled to the gills with gas, then had 2x Stabil put into the tank with the gas cap on the entire time, you'd probably be okay to leave the gas in the car and run it.
- If the car only had a small amount of gas (say 1 gallon in a 16+ gallon tank), you can probably get away with it by filling the car up with fresh fuel all the way. This will dilute the fuel which was in the tank and make it not so toxic to the bits and pieces.
Gas is a highly refined substance. One of the issues it faces is oxidation. You can note if your gas is oxidized by looking at it in a clear container. You'll see it has turned an amber color when oxidized, as fresh fuel should be almost completely clear. Oxidized gas can cause varnish and deposits which can cause clogging.
The biggest problem with today's gas is that it has ethanol in it (at least in the US). Your everyday fuel has 10%. Ethanol attracts and absorbs water. This water causes issues with rust inside your fuel tank, which will cause small metal particulates to slough off and plug the fuel filters. Not prepping the gas to be in the car for a while is what causes the issues.
In both of these cases, filling the tank all the way and putting fuel stabilizer into the fuel will help prevent the issues in the first place.
I think most of the advice which was given in the link you posted is fairly sound. It makes sense to get your engine right after treating it so wrong for 2-3 years. For further reading, this article from CNN has some pretty decent information in it.