Diagnosing The 2nd Gen GM HEI Ignition System Auto and Marine Using Common Tools

This is a demonstration on how to diagnose a no spark, weak spark, and no injector pulse concerns with this system commonly found on 87-95 GM trucks with 4.3, 5.0, 5.7, and 7.4 engines. It was also used in the some other engines such as the 2.5 and 2.8 as well. It was very common to find these ignition systems as factory equipment on marine fuel injected engines with MEFI controllers from 94-03. It was also a very common ignition system upgrade the the marine industry on carbureted engines and was called the Delco Voyager ignition system. Crusader marine started engines this system on their carbureted XL series engines in 1992. It’s a popular system and these techniques shown will help you diagnose a start/stall, stalling at idle, no spark, no injector pulse or both.