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Home >> GMC >> 1991 >> Forward Control 7.4 N >> Repair and Diagnosis >> External Pages >> Different car >> Section 3 (Engine Controls - Basic Testing) >> C-4, Basic Ignition System Checks (Gasoline) >> HEI-Est Distributor >> Spark
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HEI-Est Distributor: Spark

WARNING: This page does not describe the selected car, but rather 35 other vehicles, including the 1992 Pontiac Trans Sport, 1992 Oldsmobile Silhouette, 1992 Oldsmobile Bravada, 1992 GMC Yukon, and 1992 GMC Vandura Special. However, it is still accessible from the selected car via links, so may be relevant.
  1. If factory tachometer is connected to ignition coil tachometer terminal, disconnect it before performing tests. When removing spark plug wire from spark plug, twist and pull on boot. DO NOT  pull on wire.
  2. Using Spark Tester (ST-125), check for spark at coil wire (if applicable) and at each spark plug wire. Check spark plug wire resistance on suspect wires. Resistance should not be greater than 30,000 ohms.
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