383 BACKFIRING THROUGH EXHAUST...HELP!!!

Old 10-20-2016, 08:51 AM
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Exclamation 383 BACKFIRING THROUGH EXHAUST...HELP!!!

I have a 1969 Dodge Super Bee with a warmed 383 4bbl with Chrysler electronic ignition. Recently when I start it at idle it will BANG through the exhaust every few seconds so bad I have to turn it off. I also noticed that with the ignition key on I can touch the battery cable to the battery and the coil clicks and makes a buzzing sound for a second or two. I've tried several new coils but I get the same thing. Firing order is correct and all parts are new (fresh build). It ran great before and no changes have been made since it ran good. What could cause it to BANG through the exhaust every few seconds? My brain hurts.
I would appreciate any help.

THANKS!

David T.
Old 10-20-2016, 10:09 AM
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Tight exhaust valve setting?
Old 10-20-2016, 10:31 AM
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Unhappy 383 BACKFIRING THROUGH EXHAUST...HELP!!!

I appreciate the help but all valves settings are correct. It ran great until it sat for a month.
Old 10-20-2016, 11:55 AM
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Not Hanging open? Is it?.... Try a compression test on that cylinder, see if you might have a sealing problem? Just food for thought..
Old 10-20-2016, 01:09 PM
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I certainly will. Thanks!
Old 10-20-2016, 04:38 PM
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Late ignition timing or open (stuck) exhaust valve. Compression test YES. Air pressure test with both valves closed on compression stroke through spark plug hole, as well. Only after checking ignition timing.
Old 10-20-2016, 07:19 PM
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D -

It's either timing, valve problem or crossed wires.
And don't rule out wire arcing, a slipped timing chain or a bad control box, but the latter is VERY rare.
Since it happens all the time, the cause has to be pretty basic.

Archer
Old 10-21-2016, 06:12 AM
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Bottom of distributor cap dry, I have seen condensation mess things up.
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Old 10-21-2016, 04:35 PM
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Another possibility is a tight valve guide, only way to check is to pull the heads or you could pull the rockers and the springs to check
Old 02-05-2017, 04:41 PM
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Originally Posted by DOBZNZ
I have a 1969 Dodge Super Bee with a warmed 383 4bbl with Chrysler electronic ignition. Recently when I start it at idle it will BANG through the exhaust every few seconds so bad I have to turn it off. I also noticed that with the ignition key on I can touch the battery cable to the battery and the coil clicks and makes a buzzing sound for a second or two. I've tried several new coils but I get the same thing. Firing order is correct and all parts are new (fresh build). It ran great before and no changes have been made since it ran good. What could cause it to BANG through the exhaust every few seconds? My brain hurts.
I would appreciate any help.

THANKS!

David T.
I think you have a short in the ignition circuit or a bad ground causing a short to the coil
Check the grounds especially the strap from the rear of the block th the body...
I jad a simular issue.
I think your coil is acting as a ground ....as the short searches for a ground it finds the coil and discharges causing it to missfire.
Old 04-09-2017, 12:56 PM
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I am going to say ignition issues as fuel is building in the exhaust un burnt check all connections and look for an arched wire
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