Have a 99 Ford Taurus it runs and idles rough. Sometimes when I press the gas to go it won't go over 10mph I let off the gas and the rpm's go back down and I give it gas and it will pick up speed.

Is the Check Engine Light on? A burned valve won't cause an acceleration problem as much as it will run rough all of the time and perhaps misfire or even backfire. Only a compression test will tell. There are a lot of things that can cause your symptoms but a plugged catalytic converter, Dirty MAF sensor, stuck open EGR valve, failing fuel pump - there's a whole list of things that can cause the problem.