lean burn removal

[mopops]

this info has got to be here but being new i have not found it i have an ICM from an 80s truck- 2bbl carb (no switches) an distributor can anyone run by me what needs to be done other than that thanks

 

[Aspen500]

It's fairly straight forward. I know this is small and hard to see but, I found this in the archives. Maybe it'll help. If not, let me (us) know and we'll go from there.

Lean Burn Conversion 101

You will also need the ignition harness, with the ICM and dist. wiring connectors along with the connectors for the ballast resistor.

 

[mopops]

thank u aspen u saved me tons of time geo.

 

[Aspen500]

As I mentioned, it's fairly easy to convert. Did it on a '78 Cordoba I had about 25-30 years ago. It was still easy to find the parts and wire harness at the scrapyards then. Think it took all of about 45 minutes to do. The difference was like night and day. Assumed the ECM was bad and I'm now sure it was. Pretty much the same thing but that one said "Electronic Spark Control" on the computer. It was a 360 2brl. Ran like crap before, stalling, stumbling, hesitation on accel, really bad mpg, the works.

 

[Oldiron440]

A quick roadside repair is a points distributor.

 

[Cordoba1]

As I mentioned, it's fairly easy to convert. Did it on a '78 Cordoba I had about 25-30 years ago. It was still easy to find the parts and wire harness at the scrapyards then. Think it took all of about 45 minutes to do. The difference was like night and day. Assumed the ECM was bad and I'm now sure it was. Pretty much the same thing but that one said "Electronic Spark Control" on the computer. It was a 360 2brl. Ran like crap before, stalling, stumbling, hesitation on accel, really bad mpg, the works.

I completely agree that the swap is easy to do. I do not agree that it was likely that the ECM was bad. The fact that the car was still running means the ECM was providing a circuit-break to the coil, firing the plugs. Lean Burn, at the time, was not well understood by the technicians of the day; and continues to cause people fits. What I suspect was more likely, is that one or more of the sensors was bad. When that happens, Lean Burn goes into limp mode, providing a base "get you home" timing. At this point, the car runs poorly. Instead of fixing one of the $10 sensors, mechanics of the time (and to this day) do a rip and replace. Lean Burn was used through 1989, and was ported to even the 4 cylinder engines of the 80's. I know it seems easier to do the swap -- I did several myself. I just wish the system was better understood.