Report Engine back firing.. in Fuel System/Carbs Posted April 7, 2010 Well I finally found my problem of the backfiring and why it did it more on hills. It turned out to be a loose negative cable on the battery. Dont ask me how but at rest the contection was good enough to start the car, but on accelleration or on a hill (battery sliding back) the connector would lossen and I would loose my ground. Since tigtening the connector, things are now quiet. I really appreciate all the help from everyone. Paul.