Won't help, you have to siphon or drain the tank first. Then refill with good gas and add an injector cleaner. Diesel is oily compared to gasoline and won't burn in a gas engine, so you may have to crank motor for a while to get all the remnant out of the fuel line and filter.
Do you how much diesel? Some diesel fuel won't hurt anything as the gasoline will cut the oils down but if it is more than a gallon then the tank will have to be siphoned out and good gas put back in and then cycle the key a few times to flush what's left of the diesel back into the tank so it can get mixed into the gasoline, so it will take another tank of fuel to get all of the diesel out of the fuel system.
Search Ford Taurus Questions
Ford Taurus Experts