The timing is adjusted in the normal way - by turning the distributor. In this case the distributor is on the back of the camshaft ie. in the head but it is easy to loosen the retaining bolts so that the distributor can be rotated. A timing light on the first cylinder will enable you to read the timing mark on the front crank pulley. Normal timing is 12 degrees before top dead center. The electronic ignition in conjunction with the knock sensor (left side of the engine under the intake manifold at about cylinder three) will retard the timing when ping or knock is sensed. If your timing is correct and you still get ping I would suggest a new knock sensor. Ping or knock will destroy pistons and valves especially under boost in a turbo. It would be cheaper to fix this now than to wait for more severe engine damage and consequent rebuild.