Operation CHARM: Car repair manuals for everyone.

Fuel Injected Engine

Fig. 42 Ignition timing control system.:




Fig. 43 Ignition timing control system.:





For 1985-87 models, Figs. 42 and 43, the distributor has two separate vacuum advance diaphragms which operate on manifold vacuum. Vacuum is applied directly to diaphragm A, while vacuum to diaphragm B is controlled by an inline cold advance solenoid valve. This valve is operated by the control unit which receives signals from the engine coolant temperature, engine speed and manifold vacuum. When the solenoid valve is open, it sends vacuum to diaphragm B to improve cold engine performance.
No vacuum advance is used on 1988 fuel injected models. Ignition timing is directly controlled by the ECU.