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keep burning up ignition modules

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Old 02-23-2008, 12:15 AM
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Car: 1991 Z28
Engine: 5.7 TPI L98
Transmission: 700-R4
Axle/Gears: Moser 9" with 4.11
keep burning up ignition modules

Im using the stock distributor with a MSD remote coil and MSD 6A box. Ive been using this combo for about 9 years and i keep burning up my ignition modules, (about 1 every year). Ive tried a few different brands of modules to the same result. Will the MSD distributor help me out? I don't want to shell out $250 if its not gonna really help. Will i have to wire it up to the box different than the stock distributor? I lost my instructions that came with the 6A box. I think i remember it might just plug right in. There is a plug outlet on the box thats not hooked up right now. Is the MSD distributor that much better then the stock one?
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Old 02-23-2008, 08:33 AM
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Car: 1988 Trans Am GTA
Engine: 350 4BBL
Transmission: 700R4
Axle/Gears: 3.27
Re: keep burning up ignition modules

That doesn't make sense because the 6A should be driving the coil load with the module in the dizzy just providing a signal to the 6A and the tach.
I would think that the culprit would be either the wiring to the tach or voltage spikes coming in the key switch feed to the module (NOS solenoids closing).
I would put a blocking diode and a MOV (metal oxide varistor) between the voltage feed to the module and ground.
The diode would kill any negative spikes and the MOV would clip positive spikes to under 140V.
Like this:
(+)---l<----(-) Diode (radioshack #276-1144) $1.59
(+)---l/l----(-) MOV (radioshack #276-568) $1.99
The signal wire to the tach (if it is connected to the module) can be run thru a resistor (271-1115) $.99 to make it "short proof".
Old 02-23-2008, 12:17 PM
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Car: 1990 Pontiac Trans Am
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Re: keep burning up ignition modules

There are instructions for wiring the MSD boxes on their website: http://www.msdignition.com/

Dumb question, but are you using heat sink paste on the modules before you install them? Heat is the biggest killer of ignition modules.
Old 02-23-2008, 12:42 PM
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Car: 1991 Z28
Engine: 5.7 TPI L98
Transmission: 700-R4
Axle/Gears: Moser 9" with 4.11
Re: keep burning up ignition modules

yeah, i have been using the paste. It seems like a moisture issue too. It gets really corroded in there. Ive replaced the cap too.
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