Is EDIS-4 ignition timing can be checked with normal timing light? Cause Haynes says that special equipment must be used. I have checked my ignition timing with normal timing light and here must be a problem with readings or ignition timing itself, cause many sources like Autodata and ect. say that ignition timing must be 10 degrees BTDC but mine is 20 degrees!!! When HEGO is unpluged then - 16 degrees BTDC!!! Is that a problem due to not special equipment or its a EDIS-ECC IV modules fault?
Help needed! Please!