2002 Ford Taurus. Rough idle, almost stalling at red lights, and hard to...

[anthony]

...start sometimes.? I put a bottle of fuel system cleaner in gas and that helped for that tank of gas. The RPMs drop at red lights until the engine almost dies, Sometimes the car starts fine and sometimes it takes forever as the engine just turns over and over, I am afraid I will burn up the starter if this keeps up. When the car finally starts the idle jumps and drops for a few seconds and then levels off. The check engine light isn't on and the car drives fine sometimes but sometimes not. 3.0 liter sohc V6 with 115,000 miles. Also I use premium fuel as this seems to help. Please help, Ford dealership charges $75 bucks just to check the problem not to even fix it. Hopefully it will be something simple that I can do.