Attempting to adjust the ignition timing on this engine without specialized tools and knowledge is strongly discouraged. You could easily damage the engine.
If you suspect a problem with the ignition timing, you need to have a qualified mechanic or automotive technician diagnose the issue using a scan tool to read the computer's data. They can identify if the computer is controlling timing correctly or if there's a problem with sensors or the PCM (Powertrain Control Module) itself.