Back in the late ’70s the big three were in the soup. Increasingly stringent emissions regulations in conjunction with some long in the tooth designs made for some interesting attempts at fuel and spark management. Some of these things worked. Some sort of kind of worked. A few actually did their job pretty well, considering. In the latter category was the Chrysler Electronic Fuel Control System. Also known as lean burn, this proto-computer lived on the side of the air filter housing. Lean burn controlled ignition timing by reading engine vacuum, throttle position, and engine temperature via the miracle of computers. The core concept behind lean burn lives on today in the form of a mass air flow sensor and modern electronic engine management. Pop the cover on one of these systems at the junkyard and one is greeted with the vision of top of the line for 1975 transistors embedded in a prehistoric fly-in-amber like substance. Sometimes a few spiders will crawl out, their quality engineering work long since completed.
Editor’s note: this post was originally published on Junkyard Chronicle back in 2006. The car and/or parts in these images are long gone.