Run on with MSD?

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FastDriver

My dad had a bra
SN Certified Technician
Sep 5, 2001
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Fort Knox, KY
What's run-on? Dieseling? I've run an MSD on most of my cars and haven't had the problems that others have, except with their TFI module.
 

79 Fox

Active Member
May 21, 2019
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A van down by the river
The engine runs on because a small amount of current can leak back to the box which keeps things running. A diode in a certain place stops this flow, but we don’t know where it goes, and information is nowhere to be found.
 

RangerJoe

I leave the horn on while driving
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Apr 26, 2010
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The engine runs on because a small amount of current can leak back to the box which keeps things running. A diode in a certain place stops this flow, but we don’t know where it goes, and information is nowhere to be found.
Never heard of that before, but if current is flowing back into the box I would assume you would place it in the 12v power wire.

Joe
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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polk county florida
There is a diode on the ground wire on the belt driven hydraulic pump on the dump truck, the manufacturer found that on some installations power was feeding back through the ground and the clutch would engage with the power switch in the off position. This may be the problem you have although I've never heard of the msd box causing an engine to 'run on'.
 
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