Ignition timing control allows the timing to be set to what the user desires with RPM and vacuum, without having to change springs, weights, or vacuum advance settings. It allows the timing with boost to be adjusted to be less than non-boost conditions. If a Power Adder system is used with timing control, the spark advance can be retarded when nitrous is used. There is an idle stability function to improve idle speed control by quickly advancing when the RPMs drop, and retarding when it jumps too high at idle. It allows the cranking spark advance to be lower than the idle spark advance, to keep the engine from kicking back on the starter.