Detecting a Lean Burn conversion

[Fast Eddie B]

I'm new to modern Mopars and trying to figure out what Lean Burn looks like. I have a pair of 77 wagons. One has all the electronics hanging off the air cleaner. One does not. Both have the same carb. Both have coils and vacuum advance hoses running from the carb to the distributor.

Have these been converted and partly converted away from lean burn?

 

[commando1]

Pics of the engine bay speaks volumes.

 

[1978 NYB]

Lean Burn

 

[1978 NYB]

 

[1978 NYB]

 

[Carmine]

Actually, none of that proves anything. Plenty of people keep the lean burn air cleaner after a conversion. And there is no need to remove the wiring either.

However, a functional vacuum advance should mean the lean burn has been removed. LB distributors don't have vacuum advance.

 

[Johnny Mac]

IF they run....they no longer have the learn burn ;) lol

 

[Johnny Mac]

Actually, none of that proves anything. Plenty of people keep the lean burn air cleaner after a conversion. And there is no need to remove the wiring either.

However, a functional vacuum advance should mean the lean burn has been removed. LB distributors don't have vacuum advance.

100% correct, and probably the easiest way to tell.

 

[Fast Eddie B]

It looks like vacuum advance and there are a pile of dead connectors that look like the connectors in 1978 NYB's diagram.

The ballast resistor is rewired too.

And the car runs like top!

 

[1978 NYB]

An electronic ignition module is needed too.

 

[commando1]

Does this engine even run?

 

[Fast Eddie B]

Runs like a top. The other one runs like kaka but I'm just using that for cosmetic parts.

Looks like the connector for the distributor. There are a number of disconnected likes in there.

Looks like they disco'd the LB

 

[commando1]

Looks like the connector for the distributor.

It is a connector to the distributor.
That's why I'm wondering how it can run.

 

[Fast Eddie B]

It is a connector to the distributor.
That's why I'm wondering how it can run.

There is a wire from the distributor to the coil and a wire from the coil to the ballast resistor. The coil contact on the resistor side also has a condenser on it.

Did they just hook up an old school basic distributor?

Everything on the car works but a couple of power door locks and the dash lights.

 

[Carmine]

It is a connector to the distributor.
That's why I'm wondering how it can run.

That is most likely a connection from the old (unused) LB wiring.

 

[70bigblockdodge]

I think they put it on points. That is what Carmine said one of the unused LB connectors.

 

[Fast Eddie B]

So i could upgrade the old points to electronic.

What happens to the carb in all this? I thought it was controlled by the same spark computer.

 

[Johnny Mac]

So i could upgrade the old points to electronic.

What happens to the carb in all this? I thought it was controlled by the same spark computer.

They would not have removed the distributor to install a points style distributor. They simply converted it to electronic mopar ignition.

fact of the matter is, it doesn't much matter if its lean burn, or mopar electronic, it's fairly unreliable, and it's the absolute first thing i throw in the trash on a mopar.

IF you want to upgrade it cheaply. you install one of these...and toss all that stuff i the trash. ballost resitor, PCM, all of it.

TSP-JM6714R Mopar BB Ready to Run Electronic Distributor. Red Cap

unless it's a 383/400, and then i need to send you another link.

 

[Fast Eddie B]

They would not have removed the distributor to install a points style distributor. They simply converted it to electronic mopar ignition.

fact of the matter is, it doesn't much matter if its lean burn, or mopar electronic, it's fairly unreliable, and it's the absolute first thing i throw in the trash on a mopar.

IF you want to upgrade it cheaply. you install one of these...and toss all that stuff i the trash. ballost resitor, PCM, all of it.
View attachment 97556
TSP-JM6714R Mopar BB Ready to Run Electronic Distributor. Red Cap

unless it's a 383/400, and then i need to send you another link.

... well I wouldn't throw out the computer incase some collector wants it...

But.

What do you do about the carb that is theoretically not adjustable? That appears to be original.

 

[Johnny Mac]

... well I wouldn't throw out the computer incase some collector wants it...

But.

What do you do about the carb that is theoretically not adjustable? That appears to be original.

replace it also if it were me. I highly doubt it's original however, as i believe the lean burn carbs were electronic input carbs as well.