I am trying to get my Dad's 81 F150, 300CI running better. One problem may be some old gasoline. He had not driven it much the last 5 years, and some of the gas may be that old in it. Last fall I filled it up, and put some stablizer in, and it started this spring, used half a tank all summer, I filled it this fall and drove it home, but runs ruff.

Shold I drain the tank, and if so how? Or just put some more fresh gas in and burn it out?

Thanks for all the great advise so far.

Jim

 

What I would do is, fill up with supreme and add some fuelinjector/carb cleaner and go for a good joy ride! burn the whole tank and fill with supreme and more cleaner, go for another run you should notice a difference. Make sure you work the throttle but don't hold it to the mat or anything you might burn something.
That my 2 cents! It worked for me.
Steve