Electronic ignition started showing up in some Chrysler vehicles in 1972. The following year it became standard on all models.Externally the new electronic distributors were identical to it's breaker point brethren. Internally It's a different story, The breaker cam that activated the breaker points was replaced with an iron-core reluctor with eight sharp projections around the periphery.(six cylinder models had six) The breaker points were replaced with a magnet/coil pickup. As the distributor shaft rotated the reluctor tips come in close proximity to the pickup and the magnetic field flow. The low level "pulse" of electricity created triggers the external control box (ECU),which in turn supplies current to the coil.Since there are virtually no rubbing parts the Chrysler electronic ignition distributor is a well-performing piece with almost no maintenance. But as good as it is, we can always make it better.
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Last June I did a quickie spray can rebuild of a Chrysler 400 with hopes of it someday being installed in my '73 Fury. Since where I live we seem to be stuck in the winter that will never end. I decided to refurbish the distributor for the 400 instead of just stabbing it in and hoping for the best. Todays ingredient list pictured left to right are: Lightweight advance springs from TransDapt, Magnetic pickup coil and vacuum advance. New parts not pictured are distributor cap and rotor. |
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After removing the old cap and rotor I carefully pried the reluctor wheel off the shaft with a pair of screwdrivers. Be careful not to lose the tiny roll pin. After that I removed the vacuum advance and the pickup coil plate. |
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| The pickup coil is held on to the plate with this funky black "Y" shaped spring. |
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This is the advance plate. I've welded up the slots on the plate to control mechanical advance. After welding the slots I file them to dial in the desired mechanical advance. This is sometimes a trial and error endeavor. I probably won't know the optimum mechanical advance until the engine is running,so additional welding/filing may be necessary. But we're in the ballpark. The advance plate is retained on the shaft by a "U" shaped clip accessed with a needle nosed pliers. |
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After ditching the heavy factory springs,I lubed the mechanical advance weights with light grease and installed the new lightweight springs.With the modified advance plate installed you can see how the mechanical advance will be limited.This will insure full mechanical advance at around 2500 to 3000 rpm. |
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With Pickup and plate assembly,Vacuum advance and reluctor wheel all reinstalled It was time to set the air gap adjustment on the pickup coil. Using a brass feeler gauge set the gap to between .008 and .010. Now install the cap and rotor. |
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| Heres the finished product installed in the engine. |
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This is the venerable Mopar Performance "orange box" ECU. These provide reliable spark up to 6000 rpm which is safely in our operation parameters. But buyer beware: Chrysler has outsourced production of these units to China years ago and since then quality control has been sketchy. Some have lasted while others have failed after only a few hundred miles. Make sure your ECU is grounded and as far away from engine heat as possible. |
