There is a product for small engines (lawn mowers, snow blowers, etc.) called Sta-Bil that is supposed to prevent fuel from deteriorating. I think it's supposed to be put into the tank before storage, and I'm not sure if it's safe for catalytic converters, etc.
Anyway, if the Jeep was a an older driver, I would just check the oil level and tire pressures and fire it up. Of course, if it was pretty new, I'd consider changing all the fluids, and draining the gas tank. Old gasoline does make a good weed killer.
You'll probably be ok, though, just running it... that's probably what I'd do. I might be tempted to try the old trick of putting a teaspoonful of motor oil into each spark plug hole, or is that just to store it? I wonder if that would help engine lubrication in those first few seconds. I'd also probably change the oil before too long. Your engine *has* been sitting all summer. Hope this helps,
Robert W. Roe
1984 300SD 165,745 miles