Quadrillion

I've neglected my '85 300ZX turbo. At 160,000mi, it's still in great shape. Looks beautiful, but since I can't afford to fix the power steering leak right now, I've left it parked in the garage. I didn't start it for about a year. Over the decades, I've done that several times - and it has always started right up after sitting idle. Late last summer, the engine was running like a top. (The battery was dead as a door nail, but I used a Black and Decker 450 Amp Jump Start System to crank it.)

But now it won't start. When I engage the Jump Starter, I can hear the fuel pump come on, I think, The engine cranks and tries to fire. It will even run for fifteen or thirty seconds sounding like only one cylinder is firing. I'll pump the gas or floorboard it, but it eventually dies. I can smell gas. I don't know where to start to fix this. The gas might be bad. there was probably five or eight gallons in the tank, so I added 4 gallons of high octane and a little bit of STP carburetor cleaner which changed nothing.

Mad at myself for letting this go so long. Any suggestions? Major thanks in advance!