See Figures 1 and 2
The Dura Spark II ignition system was used on 3.8L carbureted vehicles. The Dura Spark II ignition system consists of the typical electronic primary and conventional secondary circuits, designed to carry higher voltages. The primary and secondary circuits consists of the following components:
The Dura Spark II system uses either a Dura Spark II module or the Universal Ignition Module (UIM).
The two different Duraspark II ignition modules can be identified by 2 connectors/blue grommet on the standard module and 3 connectors/yellow grommet on the UIM.
Both ignition modules perform the function of turning off current flow through the ignition coil in response to a control signal. In the Dura Spark II ignition system, this signal comes from the distributor stator assembly. Additionally, the Universal Ignition Module (UIM), can respond to another control signal from either an ignition barometric pressure switch or the Microprocessor Control Unit (MCU), depending upon the engine's calibration. In responding to this second control signal, the UIM provides additional spark timing control for certain operating conditions by turning off the ignition coil current flow at a different time than what would happen from just the distributor signal.