1974-76 Models

The spark timing control system is used only on 280Z models. Some models, however, are equipped with a dual pick-up coil distributor. On dual pick-up distributors, phase difference is 7 crankshaft degrees (6 degrees on 1975-76 models).

When coolant temperature is below 88-104°F (31-41°C) on 1974-76 models or 135-145°F (57-63°C) on 1976 models, the coolant temperature switch is on, relay is off, and spark timing is advanced. With coolant temperature above specified range, the coolant temperature switch is off, relay is on, and spark timing is retarded.