I have a 1999 Ford Contour, V6, 2.5 liter, 5 speed manual transmission with 59K miles. A 1.5 weeks ago I was doing 70 mph with a quarter of a tank of gas. My car started to buck, and lost acceleration for 3 seconds. Then that became random. I filled the car with Regular gas(87 octane) and added a bottle of STP Fuel Injector cleaner. The problem went away. When I got to a quarter of a tank again, the car bucked again. This time a filled it up with Super Unleaded(93 octane). I brought the car into the dealer, they hooked it up to the computer, and found nothing. They told me to bring it back when I get to a quarter of a tank. They told me it was not the air intake valve. Do you have an idea what it cound be?

My wife just had a similar experience this weekend. She was on her way to work and ran out of gas, yet her gas gauge registered a solid 1/4 tank of gas left. This is new because it's always been accurate up until now and the warning light did not come on either. Amazingly, she ran out of gas about 100 feet from a gas station.