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Manifold glowing red

modcon

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Does anyone know what causes a VN 3.8 to run rough and the exhaust to
glow red after idling for 30 sec at 3000rpm?
 

253@7k

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30 seconds at 3000 rpm, thats what makes it glow. That would get very hot with no air flowing over it.

Did the buic 3.8's ever run smooth? Running rough is a broad term, is it missing or just idling like cr*p?
 

modcon

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It was running sweet, then I changed the CAS, and the coil pack, then it run rough backfiring ect... so I put the original coil pack back on and still rough.
I have tryed a brand new coil and DFI but still running rough. It probably in the wiring somewhere, I have tryed all the common problem areas
 

253@7k

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I would be going with spark plug leads.
 

Shortstuff

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I know it sounds pretty obvious, but all the HT leads are on in the right order after changing the coil pack? Very easy mistake if all the leads are off at the same time!
 

modcon

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new spark plugs, new leads and the leads are on in the right order, I've checked numerous times, the manifold is glowing in just one part of the join, I'm wondering if there is a leak
 

commy92

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ide say more of a blockage. stock manifolds should not glow
 

jules

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commy92 said:
ide say more of a blockage. stock manifolds should not glow

at a guess i'd agree. a misfire won't cause the manifold to glow. take your cat off and shake it, if it rattles apparently that's a sign it's history. you can look inside a bit with a torch as well.
 

bush_basha

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yes i would 98% say its your cat, i have a V8 and it wasnt reving over 3-4 took it to the mechanics, they noticed the glowing of the and fixed it.
 
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