I was always a fan of the Lean Burn system performance. Yeah, I know the reliability sucked but when they worked I thought they were cutting edge technology. I've been looking for a similar system that would have electronic spark advance control capability only for a carburetor equipped engine. I ran into one called MegaSquirt. Is anybody using one of these? Can somebody give me a "25 words or less" explanation of what it is? Are there other alternatives?

I too, am a "fan" of sorts. Mopar was light-years ahead when it came to technology. Imagine, a 76 Cordoba/Charger/etc w/400 came with a computer on the engine.

Direct Connection was working on a "performance" version, but due to financial issues w/Mopar, it didn't come to fruition.

Can't say I've heard of what you're talking about. I've wondered if someone could actually take a LB computer and change it's logic.

My experience was that the Lean Burn systems were SO troublesome & short-lived, that dealers would "retrofit" vehicles with the lean burn problems to undo the whole system. I had a '78 Dodge Super Coupe that was all factory with the lean burn system, even replaced the computer unit with an NOS one from Rick Eherenberg, & the car still ran like total crap - felt like it was firing on 5 cylinders all the time. I disconnected the computer & installed a single point distributor & it was like adding 100 HP to the engine.

You can have the lean burn.

I know many have has similar "horror" stories, but my experiences with them was good. I changed one of my Magnums over from LB to Elect. Ign., and barely noticed any difference at all. But my story's not the norm.

I think the thread thought was how ahead of their day they were, working or not. It's like GM's V8-6-4 deal, great on paper, but was horrible in real life.

Mopar used that same computer till the OBD-1 computer days.

I'm with you Bill. I had 3 of them....1 died in the 50k miles range and about 7 years old, and other at 38k (but 30 years old), and another was still working when I traded the car at about 10 years old and 80k+. But when they were working, they were excellent units from a performance standpoint...always fast starting and very responsive IMO.

A DC version would have been sweet!

While plenty of units did go bad, I think a lot of them got replaced when they were not bad (particularly where the problem was not resolved with replacement). They did use several pickups and sensors on the engine which folks seemed to overlook when doing their diagnosis. And of course, this was the first time a lot of techs were doing computer diagnosis, which did not help matters any.

On lean burn... Megasquirt designs EFI systems for retro-fit. You buy the plans and main components and assemble the brain box yourself.

With EFI and a wideband O2 sensor its not hard to set up leanburn... simply map lean AF ratios and extra ignition advance at light load. Honda I believe sold a car set up this way in Australia. Mileage was great but its not compatible with a 3 way catalyst so it couldn't make US emissions.

The trick is to map correctly so you get the lean burn benefits without trashing the engine through detonation or excessive temperatures. Without a lot of instrumentation and testing this is hard. I've got a little bit of leanburn dialed into my EFI BB. At a steady light throttle cruise its running around 16:1. As soon as the throttle is opened and manifold pressure increases, it adds fuel and goes back to normal operation. I just don't want to push it too far.

MS-1 with the 'extra' code loaded could do his ignition-only system as well.

FWIW, lean burn WAS ignition-only. The lean burn carbs were not computer controlled, they were simply smogger era emissions jetted thermoquads. After lean burn went the way of the dinosaur, we got the electronic feedback carbs. On those ones the computer modules also did spark and the computer units themselves were a lot more reliable than the old lean burn computers.

Thanks guys. Appreciate the input.