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Today my car started running like crap, misfiring & popping. I went home & checked it out & three of my plugs were fouling & totally covered with carbon & the rest are turning black also. I have a 600cfm Edelbrock(was fine on my 283) with vortec heads & just short of 10:1 compression on a 355. I have a Mallory Unilite with r44lts AC plugs gapped at .035. The only difference in my ignition system from the engine swap is that I put on an Accel canister coil(42,000max volts) in place of the Mallory high output(51,000max volts) coil that I accidently broke. Could this be too weak to get a good spark? I really cant believe that the 600cfm carb would be too rich. Any thoughts??

Thanks!!
 

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My plugs, on a very similar setup, went from the condition posted in Pic #1 to the condition in Pic #2 just by spending a little bit of time setting the idle mixture screws and idle speed properly.

ANY carb can dump way too much fuel into the motor at idle and cause this symptom of poor idle mixture. It seems to be a common problem.



 

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was anything done shortly before this problem....was it all of a sudden?

may not be the carb is too rich, but just not being lit..
 

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Extended periods of idling and running outside of an engine's rpm range(tuning inthe garage without taking the car out for a good run )seemed to carbon foul my plugs pretty quickly.This caused backfiring and rough running till I changed them ,and they were fairly new plugs.Just a thought..
 
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