AMC Eagle

[MadMan]

Originally Posted by beat_truck

What was the actual benefit of it supposed to be, though? It basically read the ported engine vacuum and advanced the timing? Didn't a regular vacuum advance distributor do the same exact thing, and according to many people, do a better job of it too?

https://www.allpar.com/mopar/lean-burn.html

The short version is that the guys at Chrysler discovered that if they had super precise control over the ignition timing, they could run the carb super lean and still achieve the same performance as a richer mixture with a regular old fashioned vacuum advance distributor. Yes, it was motivated by meeting emissions standards, but in theory that sounds plenty better than the 'old way' and it should improve fuel economy and keep the same performance.

It was a simple system, but not as simple as you might think.

The system measured:
1. Engine speed (r.p.m.).
2. Engine load. [likely the MAP vacuum]
3. Throttle position.
4. Speed of throttle movement.
5. Air temperature entering the engine.
6. Engine coolant temperature.
7. Carburetor throttle open or closed.
8. Engine starting.

As for the old fashioned carburetor and ignition system being 'better' - that sounds entirely typical of all the grumbly old farts in the repair industry. It's not that anything is 'better' it's that they are used to something being a particular way. They all said the same things about fuel injection, front wheel drive, unibody, disc brakes, MacPherson struts, I could go on and on. I'm sure that 'many people' also thought that hand cranking your engine was 'better' than having a starter, and that acetylene lamps were better than those new-fangled electric lights. lol You could probably go even further back and some guy would've said that steam was better than internal combustion.