Ballast Resistor on Lean Burn

hemihead

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A Buddy asked me where the Ballast Resistor was on his 85 Dippy with Lean Burn . I thought a minute and realized ,
I don't know . Is it integrated into the Lean Burn ?
 

Jack Meoff

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Welcome.
There is no ballast resistor.
That job is taken over by the pickups in the distributor.
There's a start pickup and a run pickup in the lean burn distributor.
 

lowbudget

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I don't think a lean burn has one. This is from slantsix.org's lean burn conversion. "The 12 volt coils used on Lean Burn engines didn't have ballast resistors. The story seems to be that the Lean Burn computer had an internal ballast resistor. An aftermarket coil that does not require an external ballast resistor could be used to eliminate the need for a relay and simplify the wiring. In general it is a good idea to use the factory coil designed for the ignition system being installed instead of re-using the coil from the old system." I didn't have time to do mine last days off but I bought a new ballast resistor and coil for mine. I will know next days off!
 

Jack Meoff

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Slants didn't get the spark control computer till mid 80's so they did have a ballast resistor till then.....should have asked if your Dip was a slant....I assumed it was a 318.

The spark control had no ballast resistor it was incorporated into the system. If memory serves the issues that would normally point to a ballast would then point to the start or run pickups in the distributor.
 

Monkeyed

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I don't think a lean burn has one. This is from slantsix.org's lean burn conversion. "The 12 volt coils used on Lean Burn engines didn't have ballast resistors. The story seems to be that the Lean Burn computer had an internal ballast resistor."

So if you had a ballast resistor problem you'd have to replace the computer to correct it..?
 

Jack Meoff

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So if you had a ballast resistor problem you'd have to replace the computer to correct it..?

As far as I've known.
An absolute no start could be the computer....amongst other possibilities. A start and die when the key is released scenario like with a faulty resistor points to the run pickup in the distributor.


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Darter6

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News to me, do you know what year this started? I have a 79 Chrysler with lean burn, air cleaner mounted computer and it has a ballast.It has a single pickup.Maybe when they went to a dual ?
 

Jack Meoff

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Never heard of that one.
It's all factory?
As far as I've ever known.
ECU with ballast....computer no ballast.
Must be the single pickup....I know on the duals one pickup takes the place of the ballast.
 

BHA43

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Without having wiring diagrams in front of me I'll chime in.
My 78 Kit Car with E58 air cleaner mounted lean burn has a 2 wire ballast on the firewall. Not arguing that the dual pick up ones had no external ballast resistor or not. But the dual pickups can not replace the resistor. A resistor is just that it reduces voltage from Bat/Alt. 12-14 down to 6-8 usually. The pick ups are magnetic switches that trigger the ign system. My guess is the later ones have a transistorized resistor built into the ECM. Sort of like when they went from a 4 pin brain box used with a 4 wire resistor to the 5 pin box that used a 2 wire resistor for the coil and had the internal resistor to reduce voltage to the brain box.
 

Kaitsu

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I think that I can finally donate to the community with my knowledge about emissions and especially Lean burn and later Spark control. Lean burn was first launched in 1976 in Cordobas, then, later adopted into most of Chrysler Corp passenger cars. They changed the name from Lean burn to Spark control in 1978, I don´t know why.

Single pick-up distributors are used in all other cars, only 360 engines and Californian Slants and 318s got separate run and start pickups. These also used Combustion computer rather than Spark Control computers or Lean burn computers as they´re labeled on top of the computer.

The computers themselves, were analog prior to 1980, when they started to digitalize the computing system for more reliable sensor reading and computing process. This digital system also enabled the use of O2 sensors with feedback carbs.

I hope I solved some guestions!
 

Aspen500

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I had an '81 Dodge D150 (318) back in the '90's and it had a dual pickup distributor with a relay (might have been a dual relay?) on the firewall to switch between the start and run pickups. It didn't have, and never had any kind of computer. It ran the standard Mopar ECU on the firewall. I always thought it was kind of an odd setup but it worked just fine.

I ASSUME, one pickup was timed different for easier starting. Never did look into it to satisfy my curiosity. Damn, I sure do miss that truck!
 

Kaitsu

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The start pick- up is used during cranking when the computer enters into "start" mode. It gives the maximum amount of advance for about 1 minute from turning the key, trying to avoid engine stalls during warm- up period. If the coolant sensor tells the engine its warm enough, it lowers the warm up period. I can provide more info on ECU- single pickup distributor by evening when I get to the shop.
 

Jack Meoff

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The start pick- up is used during cranking when the computer enters into "start" mode. It gives the maximum amount of advance for about 1 minute from turning the key, trying to avoid engine stalls during warm- up period. If the coolant sensor tells the engine its warm enough, it lowers the warm up period. I can provide more info on ECU- single pickup distributor by evening when I get to the shop.

Please do.
 

Miradaman

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My '81 Mirada came with a 2bbl 318, and the lean burn system. There was a dual ballast resistor on the firewall, with 4 wires hooked to it. IIRC one resistor was .5 amps, and the other was 1.5 amps. The single one for vacuum advance distributor was 1.5 I think. Mopar Performance has the conversion kit if you want to change it.
 
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