FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: fryedaddy on August 16, 2023, 02:31:03 PM
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since i changed from a msd box to a gm module i noticed my engine,when i turn the key off dont really keep running but i makes one little noise after you turn it off.it sounds like it wants to keep running but it dont do it but for a second or less.would this be a sign of too much timing or too little.its not bad but its noticeable.
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Just an allergic reaction the the Chevy box. Did you check your timing? As it changes with different boxes.
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Check your idle speed. Run on can also be caused by high engine temperature and hot spots --like glowing carbon bits-- in the combustion chamber, or too hot of a spark plug. The module won't do this. It is just a switch for the coil, and once you turn off the power going to the coil, the module is dead.
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idle is a little high and its on pure pump gas.i usually add a 5 gallon can of 110 when i fill up
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Wouldn't Be A Bad Idea To Install A Diode On The + Wire Going To The GM Module, If There Is One. Easy To Do, And See What Happens.
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i turned the idle down from 1000 to 875-900. it made no change,it still does it.i usually keep a little 110 in it,sometimes straight 110.right now it has 100% pump gas in it.could it be it just needs better gas.my dad ran some straight 87 in his gt fairlane one time and it pinged and runoff too.
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It depends upon where your octane tolerance is. A high compression engine will benefit from more octane to suppress preignition, a colder plug, and an anti-diesel solenoid that closes the throttle blades completely so the engine can't get any air. Again, the module can't do this. When you turn off the key, the primary side of the ignition goes dead and without any primary current, there can't be a secondary current. To satisfy your curiosity on this, hook up a multimeter to the coil +. You will see your primary current when the engine is running and it will go to zero as soon as you turn off the key. If it doesn't do that, there would have to be a problem in your wiring from the key to the coil. How clean is your combustion chamber? If you suspect it could be carbon deposits lighting off, you might try the water down the carburetor to clean up the chambers.
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cant be deposits,new bbm heads and the engine is almost still new,pistons are still shinny.i headed to town to get some 110, i will let you know how it does
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the problem turned out to be the plug wires were bad,i guess causing unburnt fuel in headers.i had 4 wires that tested bad.it quit trying to runnoff immediately after changing the bad wires
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Thx for the issue update/solution !
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A diode is recommended for alternator feed back.