Ignition Timing

On Accord models, ignitor inside distributor triggers ignition coil based upon its own pick-up coil signals. This trigger signal is further modified by both vacuum and centrifugal advance mechanisms. The vacuum advance mechanism consists of a dual-diaphragm which operates on manifold vacuum. Vacuum to the outside diaphragm is controlled by an ECU-regulated vacuum solenoid. This solenoid will pass vacuum to outside diaphragm when vehicle is cold. This allows additional advance to improve cold engine performance.