OK, I have been experiencing these same symptoms for at least 2 years now. The problem occurs at times when 1) It is hot out, and 2) When the RPMs are low such as Stop and Go Traffic or city driving. It first occurred while I was on my way out of town and passed through a construction area where traffic was stop and go. Died on the freeway. It started again after a few minutes and I made it off an exit to a shop. It took them an hour to get to it and by then they couldn't find anything wrong. I finished my 1800 mile trip without any other problems. Over the course of the past couple years it has happened more and more frequently under the right conditions. On another trip of about 1500 miles I pulled into an account and it died. An employee there called a mechanic she had recently worked for. He pulled the little screw-on cap off of the Fuel Rail Pressure Relief valve (like a tire valve only bigger) and had his helper crank the engine. At first nothing but air came spewing out. Finally gas started squirting out. (Yes, all over the engine. It was hot enough it just evaporated almost instantly.) He said it's your ___ ___ ___. I didn't understand what he said, but something like your Fuel Return Pump or something. I have since learned there is no such thing, but it had something to do with the fuel returning to the tank. I also think he said it was somewhere under the chassis. Anyway, he told me that until I could get one, that if it happened again I could just release the pressure like he did and it would get me going again. I have done this for nearly 2 years and has at least kept me going many times. It is definitely a fuel problem. The reason it has low power is because there is so much vapor in the system that not enough fuel is reaching the engine, but it can run at a low RPM, but have no power. When you give it more throttle it changes the air/fuel mixture and stalls. It is a vapor lock of some sort happening, but I still don't know why. It happened several times again yesterday, so I took it to O'Riley Auto Parts and used their tool to test my fuel pressure. After I had vented the system I was getting 50 PSI fuel pressure. That's why I am convinced it is just a vapor lock - But Why??? I hope this helps someone. It would be great if we could all figure this out!