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Old 04-03-2021, 07:35 PM   #1
cj847
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Join Date: Sep 2016
Location: Ft Smith, AR
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Diagnosing a miss

I am trying to diagnose a misfire on my 71 with SBC. But, I cannot figure out where to plug in my scan tool. Any ideas.....

I decided to go old school and held a piece of cardboard over each tailpipe to try to determine side to side, but couldn't tell. Finally figured out it was number 8 wire burning and shorting to the exhaust manifold. You can see the sparks even in daylight....
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Old 04-03-2021, 08:20 PM   #2
tim_mc
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Re: Diagnosing a miss

Glad you found it...it was #3 for me. Burned through the cap and was shorting on on the header. I had the sleeves on them, but it wore a spot through the material where the 90 degree boot was in firm contact with the header. Swapped out the wire with a 45 degree one that gave a bit more clearance Clarence and replaced the heat resistant sleeve. All good now.
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1967 C20, 350 SBC w/Comp roller cam, 700R4 w/3.42 posi, PS, 4-wheel PDB, Old Air AC & GM Tilt column.

Last edited by tim_mc; 04-03-2021 at 08:26 PM.
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