I was working overseas for six months and my car stayed in the garage in the meantime. Before stopping it, I filled the gas tank but otherwise did nothing special.

Today I replaced the battery, which was completely flat and started the engine. After some local trip, I took it for a longer drive. After a hundred or so miles, the car started to behave weirdly. While accelerating, it started to stall, very much like a fuel cut-off. First under heavy load, after a while under medium load. I just made it to a gas station, where the engine stopped completely. I cranked, but received no response; the engine did not start although the fuel gauge showed more than a quarter full.

I thought the fuel in the tank somehow got congested and clogged the fuel filter or something else.

I refilled to full tank, cranked the engine. It started at first turning and after that it seems to behave normally. A couple of times I accelerated up to the redline; no buckling, it accelerates beautifully just like it used to be.

Still, I am baffled what caused the strange behavior. Obviously it must have been something with the fuel supply. Can the gas go wrong while staying long in the fuel tank? Or something got clogged, and by opening the fuel cap I removed the congestion?

PS. I received no CEL or warning light.

Vapor lock from the hot wheather?

It is quite possible. After stopping the engine for ten minutes for refueling the the problen seemed to solve itself. (Fingers crossing). It was really warm that day, well over 100 F.

Since then no simptomps. Service folks told me something must have been wrong with the fuel pump. If i really want it replaced they will do it, but they don't think it is necessary.