GM Blazer/Jimmy/Typhoon/Bravada 1983-1993 Repair Guide

Ignition System


The gasoline models covered by this guide utilize an HEI distributor ignition system. On earlier models, this distributor is equipped with mechanical and vacuum timing advance devices to adjust the ignition spark advance curve. Most later model distributors are equipped with Electronic Spark Timing (EST) and ignition spark advance is electronically controlled through a computer module.

For more information on ignition systems, please refer to Engine Electrical of this guide.