Ignition System - HEI: Description
NOTE:
Some Chevrolet and GMC light truck models with 5.0L 4-Bbl. (VIN LE9) engines are equipped with Electronic Spark Control to combat detonation. ESC models have 5-terminal electronic modules in the distributor, while non-ESC models have 4-terminal modules.
The Delco-Remy High Energy Ignition system consists of a battery, ignition switch, ignition coil, spark plugs, primary and secondary wiring, and a special distributor assembly.
The distributor housing and cap contain vacuum and centrifugal advance mechanisms, an electronic control module, pick-up coil, pole piece (with internal teeth), timer core (with external teeth), rotor, distributor shaft and a capacitor for radio noise suppression. Some distributor models also include an integral ignition coil.
Full battery voltage is present at the battery terminal of the distributor in either the "START" or "RUN" position, as no ballast resistance wire is used.