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backfire thru carb

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Old Sep 14, 2008 | 07:44 PM
  #1  
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From: penngrove ca
Default backfire thru carb

I have a backfire (all the time) thru the carb (CarterAFB)in 76. Rotor, cap, wires all new, new plugs installed, comp check all good. Checked vacumm at EGR and vac adv. at dist. No vacuum, The vacuum comes from the front of the eng. something called an EGR TVS. Anybody know how to check and replace? Other thouhgts?
Thanks
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Old Sep 14, 2008 | 08:04 PM
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You could have a serious timing issue. Either the distributor is misindexed badly or set way way off or your timing chain has slipped a few teeth.

Sounds like the firing is taking place when the intake valve is open maybe.
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Old Sep 14, 2008 | 08:07 PM
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From: Cedar,BC
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Sounds like a broken rocker arm or worse, a wiped cam lobe.Pull off the covers,chances are you'll see it right away.
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Old Sep 14, 2008 | 09:00 PM
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Originally Posted by tfi racing
Sounds like a broken rocker arm or worse, a wiped cam lobe.Pull off the covers,chances are you'll see it right away.


Time to pull the valve covers off.

-Mark.
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Old Sep 15, 2008 | 07:37 AM
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maybe a friend swapped plug wires as a joke.
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Old Sep 15, 2008 | 06:15 PM
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check the firing order
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Old Sep 15, 2008 | 07:40 PM
  #7  
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I had the same symptoms on mine. 3 cam lobes were pretty much gone.
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Old Sep 15, 2008 | 07:45 PM
  #8  
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Ripforrey....When you find the problem let us know. These guys could be right as you will still have compression with worn cam lobes.
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Old Sep 15, 2008 | 11:00 PM
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yup... I agree with tfi racing, My Z28 was doing the same a few yrs. ago
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Old Sep 16, 2008 | 02:13 AM
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Originally Posted by c31980
check the firing order
thats what mine was, rofl
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