System Description

COMPONENTS
- The Electronic Ignition Low Data Rate Ignition System -- consists of a crankshaft-mounted hall effect sensor for generating the Profile Ignition Pickup (PIP) signal, a camshaft-driven hall effect Camshaft Position Sensor (CMP), a 6-tower coil pack, and an Ignition Control Module (ICM).

OPERATION
- The Electronic Ignition (EI) low data rate system eliminates the distributor by using multiple ignition coils. Each coil fires two spark plugs at the same time. The plugs are paired so that as one fires during the compression cycle, the other fires during the exhaust stroke. The next time the coil is fired, the plug that was on exhaust will be on compression and the one that was on compression will be on exhaust (the spark in the exhaust cylinder is wasted but little of the coil energy is lost). Three coils are mounted together in a "coil pack". The coil pack has three coil wires, one for each coil. The crankshaft sensor is a digital-output hall effect device that responds to a rotating metallic vane mounted on the crankshaft damper assembly.

- The Powertrain Control Module (PCM) determines spark angle using the PIP signal to establish base timing. Spark Output (SPOUT) is sent from the PCM to the ICM and serves two purposes: the leading edge fires the coil and the trailing edge controls the dwell time. This feature is called Computer Controlled Dwell (CCD).