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post #1 of (permalink) Old 03-21-2001, 11:57 AM
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Ignition Module - what does it do?

Okay - 1988 I 258; upgrading to TR today (Nutter Bypass already done). My question is this: What does the Ignition Module do? I notice all the wires going to the Distributor originate from the Module. Can anyone tell me the Coil's, Distributor's, and Module's roles?

I plan on adding a MSD 6A later this week, and I noticed some of their schematics bypassing the Distributor completely, yet others wired to the Dist. Do I disconnect the old Duraspark Module when I add the MSD 6A?

I'll let you all know how the Sahara runs after the TR upgrade (wish me luck).

I258, TR TFI, MSD 6A, nutter bypass
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post #2 of (permalink) Old 03-21-2001, 09:36 PM
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Re: Ignition Module - what does it do?

Basically it controls the ground for the coil. A coil is just a transformer. A transformer will not work with DC voltage, it just becomes a magnet. The moment you take away the DC voltage, the magnetic field collapses, and "induces" voltage into the secondary windings, and thus, spark. Think of it as "points closed, then points open", or "transistor on, then transistor off". The distributor does two jobs, first primary (low voltage), which turns on and off the module. Second, is the secondary (high voltage) , which distributes the high voltage spark to the proper cylinder.

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post #3 of (permalink) Old 03-21-2001, 11:14 PM
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Re: Ignition Module - what does it do?

I disconnected the connector at the distributor and hooked the msd directly to the distributor like it is shown in the instructions. I still need to hook up my tach since it was triggered from the ignition module.

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post #4 of (permalink) Old 03-22-2001, 12:37 PM
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Re: Ignition Module - what does it do?

Thank you WILL & dorfs. I found at least three different applications which appeared to meet my needs, but that meant there were two too many! I was concerned b/c one was a 'swap' set-up for the Duraspark (p/n 8813 - Jeep Installation Kit), another was for a coil-harness(p/n 8874, and the third was for a hook-up from the Duraspark Module (p/n8869); hence, the confusion on my part.

This is why I was questioning the roles of the Distributor, Coil, and Ignition Module. BTW, should I disconnect my Duraspark once I hook up the MSD 6A?

I258, TR TFI, MSD 6A, nutter bypass
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