While we’re under the hood...

Fast Eddie B

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what does everyone do with the defunct Lean Burn ‘bay junk’?

I still have the LB unit bolted on to the air cleaner and all the wiring intact. I was thinking of leaving the air cleaner whole for nostalgia, but should I cut out the terminals from the wiring harness?

And while everything but the cruise control works, I got a pile of disconnected terminals everywhere...

Are they all related to the old LB?

Lean burn
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Three
Behind the distributor
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Two coming up from under and in front of the dizzy

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And a pair coming off the ballast resistor...
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I kept the air cleaner looking stock, but I have the ECU mounted on the firewall like a 74.
 
How did you wire the "new stuff" in? Using an adapted factory harness or with something you fabricated for the new items? No common items in the harness?

To remove all of the not-needed ELB items, you can get a service manual for the model year of your vehicle and peruse the wiring harness schematic "maps" to find what all went to the ELB computer, distributor, etc. and selectively remove it surgically. I suspect there should be one main harness it all relates to, from which everything branched off from.

Personally, I liked what I heard and saw at the dealership when the ELB system first came out. The engines were more throttle responsive and were quieter than the earlier model year's engines (at least in the Chryslers I saw back then). I was proud of Chrysler continuing its "calibration modification" orientation in emissions controls, as Ford and GM had to use "after-treatment devices", PLUS NO catalytic converters on the original ELB cars, which I considered a major feat.

It was my observation that as with a good bit of Chrysler's engineering innovations back then, electronic ignition being one of them, many techs didn't understand how things worked (compared to distributor weights, springs, and vacuum advances), so it was "bad" and another reason for the cars having to go back to the dealerships for service (which the independent shops didn't like, obviously), BUT it also related to many not desiring to learn new things, from my observations. Years later, when GM had electronic engine controls, all was fine.

I also know that as the systems aged, few knew how to really troubleshoot them. Chrysler had their "checker box" for the systems, which seemed to "Fail" many boxes whose failures could have been related to other things in the wiring harness itself. The whole system worked on voltage and resistance, which could also be affected by poor wiring connector integrity, by observation, or degraded ground connections.

Oldsmobile had a similar system that was optional on the later '70s large cars. A one year item due to low installation rates, but those who had one of those cars raved about how it got better fuel economy and such.

The Chrysler ELB helped get us into the '80s and the more advanced/sophisticated systems of the later years.

The key to the system was the leaner carburetor calibrations at cruise, which needed a different distributor advance map to make happen. Which was best done electronically than mechanically. By 1980, the "lean burn" part was gone, leaving the Electronic Spark Control system.

The problems I saw with "Conversions" were that many got an aftermarket electronic ignition system (hopefully the Mopar Perf full kit), went to the auto supply and got a reman TQuad (whose metering calibrations were not usually a good match), replaced components and TRIED to get it to run right after that. Not performing as desired, the cars were sold CHEAP and fell into hands that ended up trashing them instead of spending money to see what the prior owner had screwed up in the conversion. And things went downhill from there, by observation.

To me, back-dating to about 1972 specs should have worked better. I suspect the shops that did these things had little ideas of how to better match what they installed to the engines. It always was interesting to see how private shops talked bad about the Chrysler "electronics" systems, but when GM came out with very similar things a few years later (possibly with higher quality wiring harnesses AND better training), it was "all right". After all, if General Motors does it, it has to be good?

In my non-Chrysler product work place, we traded for a Volare wagon that wasn't running well. Had the ELB 318 in it. Not running well was the reason it was a trade-in. With a Chilton's service book on those cars, our tech was able to diagnose and FIX the car using a Volt-Ohm Meter. It took a while, but it was repaired with little parts expense and several hours of labor. BUT it also took a motivated tech to do the job, too! And running well, it went to the used car auction. Be that as it may.

I also fully understand where we are today, with many components having no available parts (other than some of the NOS items which appear every so often), so retro-fitting is more necessary. I suspect that many now doing this deal are focused on doing it right, rather than hacking it up (as obviously happened back then, by observation). By this point in time, everybody's much more comfortable with electronic engine controls, than back then, plus with a better understanding of "things computer" and how to do the wiring harness items to a much higher degree of execution.

It might take some time and focus, plus knowing what the various components were and did, but you should be able to use the wiring schematics for your model year (and possibly a prior year pre-ELB) to make sense of what you have and to surgically remove the not-needed harnesses.

I know that my observations can vary from what others saw and experienced. Each had different experiences/observations in this area, which I respect and understand.

Keep us posted on your progress, please.
CBODY67
 
I didn’t replace anything. Just found I all sitting here. This was converted a long time ago. I’m just thinking of what I can clean up. Maybe I’ll just tie them up with some zips and leave them tucked in there.

I think my new module is what I tripped over on the inner fender.
 
I didn’t replace anything. Just found I all sitting here. This was converted a long time ago. I’m just thinking of what I can clean up. Maybe I’ll just tie them up with some zips and leave them tucked in there.

I think my new module is what I tripped over on the inner fender.

There was a lot of extra wiring with the lean burn package. If you someday plan to put the car back stock, you would probably want to leave that stuff in place as rewiring the car to reinstall the lean burn would be a major PIA at some later date. I would do as suggested and fold up and zip tie the existing wiring to preserve it. Probably a good idea to tape up the ends of the connectors while you are at it. This won't be as clean looking as removing all of the unused wiring, but at least it is still there for a future factory correct restoration by you or a subsequent owner.

Dave
 
There was a lot of extra wiring with the lean burn package. If you someday plan to put the car back stock, you would probably want to leave that stuff in place as rewiring the car to reinstall the lean burn would be a major PIA at some later date. I would do as suggested and fold up and zip tie the existing wiring to preserve it. Probably a good idea to tape up the ends of the connectors while you are at it. This won't be as clean looking as removing all of the unused wiring, but at least it is still there for a future factory correct restoration by you or a subsequent owner.

Dave
I think that is the logical choice. What I haven’t heard is ‘everyone just cuts it off and seals it up’.

I doubt this will ever go stock, but who knows. I will let the next owner decide in 20 yrs.
 
Forgot to comment on my wiring. When I did the wagon, the whole wiring harness was removed, tested, and repaired/ rewrapped as needed. During that process I removed all of the LB connections, so my harness is essentially 74-76 non LB spec. I am using the 4 pin ballast resistor set up from a 75 parts car ( I see your connectors are dangling) I used the distributor connectors from my original harness (those seem to be redundant and unconnected on your yours?).

I was not hard to do, and I have no intention of ever trying to Frankenstien a working LB setup again since the old Electronic Ignition is what I'm used to and "stone-axe reliable". Although I really respect those that have got their LB set ups back to working condition.

I have my wagon really dialled in and averaged 18.9 mpg on the last road trip.

I just left this air cleaner / pie tin/ computer alone to retain the stock look. Besides, they always look terrible with riveted/ screwed on metal patches to cover the computer vents.
 
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First, thanks to CBODY67 for that excellent write-up about Lean Burn. I also fought with ELB systems (and the annoying hoses of Evaporation Control systems) at a Chrysler dealership in the mid-70s as a young and slightly more "enlightened" mechanic regarding electronic doings, and he's right on.

And I totally agree that a surgical removal of the ELB components and wiring is the proper thing to do if you plan to show the car at all. Recognizing that I'm something of a nutjob about an OEM appearing underhood, please consider:

  • Keep the ELB "look" of the air cleaner, etc. That's cool, and will be the subject of a lot of fun discussions, questions and reminisces.
  • That car will never, ever be restored to a fully functioning LB system. Why should it be? Remove that stuff!
  • If it's going to have the hood up at shows, a bunch of zipped terminals and wires is not only ugly, it looks like something has been hacked or improperly fixed by someone who doesn't know what they're doing. Remove that stuff!
 
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First, thanks to CBODY67 for that excellent write-up about Lean Burn. I also fought with ELB systems (and the annoying hoses of Evaporation Control systems) at a Chrysler dealership in the mid-70s as a young and slightly more "enlightened" mechanic regarding electronic doings, and he's right on.

And I totally agree that a surgical removal of the ELB components and wiring is the proper thing to do if you plan to show the car at all. Recognizing that I'm something of a nutjob about an OEM appearing underhood, please consider:

  • Keep the ELB "look" of the air cleaner, etc. That's cool, and will be the subject of a lot of fun discussions, questions and reminisces.
  • That car will never, ever be restored to a fully functioning LB system. Why should it be? Remove that stuff!
  • If it's going to have the hood up at shows, a bunch of zipped terminals and wires is not only ugly, it looks like something has been hacked or improperly fixed by someone who doesn't know what they're doing. Remove that stuff!

I am going to respectfully disagree. If we are talking about showing a car in a stock class, there will surely be a judge that knows the car came out with the LB and what the routing of the wiring and hoses should be. If any of that is missing, there will be significant points deducted. One of the things that happens when the various manufacturers design something that is a demonstrated POS in the field, is that those defective or poorly designed components tend to be discarded or the cars have a very low survival rate. Over time, that makes the few surviving original examples worth more because they have not been modified. Will this happen to lean burn cars any time soon? Probably not. But 50 years from now, an original working example is likely to be a very rare and desired collector car.

I would point out the example of the early fuel injected cars produced by Chrysler in the DeSoto line, all were issued recalls and the injection was replaced with conventional carbs because the factory could not design a repair to the electronics that would work. About 4 or 5 survive today with the injection intact and because of their rarity they are among the more desirable Mopar collectables.

If there are no plans to show the car or restore it to factory status, You can probably remove the extra wiring especially if you just want a clean driver automobile.

Dave
 
Oh, you've got to have the pretty decal on the computer too...
performance graphics sell them.

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I am going to respectfully disagree. If we are talking about showing a car in a stock class, there will surely be a judge that knows the car came out with the LB and what the routing of the wiring and hoses should be. If any of that is missing, there will be significant points deducted.

I see your point, Dave, and normally I would agree. But assuming it's a concours show [Pebble, Amelia?] with seriously knowledgeable judging, that means that all the other components that would be hooked to those wires and hoses must be there as well, and apparently that stuff is missing on this car. And if they're NOT there and everything is dangling, you'll really see significant points deducted.

If it's a "regular" car show that 99% of us attend, I can't imagine there's a judge out there (other than yourself! :D) who would recognize the missing "junk", as Fast Eddie put it. And there's my point about zip ties and general underhood ugliness.

So Eddie has a choice to make. Return it to full OEM appearance (but not really working) or surgically remove hoses and wiring.

And then worry about what happens in 50 years.

:rofl:
 
Another point: My underhood is pretty good, but I'm using a brand new Street Demon carb (love it!). My excuse? It's totally invisible under that giant filter housing. Pebble Beach can kiss my ***! :icon_fU:

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Interesting note, is that I've seen different types of computer decals over the years others said "SPARK CONTROL COMPUTER" or "COMBUSTION COMPUTER" then the "ELECTRONIC FUEL CONTROL SYSTEM" 80's version.

But the only one being re-popped in the "SPARK CONTROL SYSTEM" decal.

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6476681-1985LeanBurncomputer.JPG
 
Frankly... I can't stand the open maw car show look. Close the damn hood unless someone asks to see the engine in it.:rofl:

Do you drive down the road with your hood open? It completely ruins the look of a car in my opinion. Most annoying to me are the B bodies with their hoods propped up on stilts. All the engines look pretty much the same anyway, except for the cross ram Chryslers lol, but then I can ask, some may have more chrome but who cares, I sure don't, the beauty of cars is how they look as they go down the road, not all in a row yawning, car after car, after car....
Rant over.
 
I can understand each of the "remove" or "hide" orientations for the ELB wiring. In the "hide" orientation, execution could be key. IF somebody might look to see about the connector on the bottom of the computer box, see none, then they know what has happened. End of discussion, OR they might ask how it was done. OR the connector could still be plugged in, but the wiring snipped and taped to the bottom rear of the air cleaner, out of sight. IF they look to see where it goes, then they might have an idea of what they're looking at, which can start other related discussions. All good.

As for originality, unless it might be a concours-type judging (which most general car shows are not) then no deductions of any kind for "non-stock". Might get more deductions if the air cleaner was painted engine color!

In general, I don't suspect many Mopar people will complain. Just as the DC/Mopar Perf electronic ignition kit installation is totally allowed as an acceptable modification/upgrade. No big deal. Even THAT one can be successfully hidden (as I did on my '67 Newport).

Funny you mention the Street Demon, Trace! It's certainly a modified TQuad design. Especially with the phenolic float bowl option.

Enjoy!
CBODY67
 
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