timing a 1.0 geo?

i think my motor is off time(backfiring and such at higher prms). where should the timing marks be on the degree marks by the crank? do you have to unplug anything to get correct timing like on hondas or anything? any help would be greatly appreciated!

The timing mark on a 1.0l should be at 8 deg. before tdc if I am not mistaken.And to time it you need to short the plug on the right side of the coil if you are standing at the front bumper,but on different models the connectors you hot wire across are different .If you can find a manual to read it will tell you which are correct