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#1
04-07-2004, 02:04 PM
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I have been putting my new (rebuilt) Pontiac 455 through the paces and have found a problem with periodic bogging/nosing in on heavy acceleration at about 3500 rpm; it has been suggested to me by one shop that my carb's float bowl may be too small (I am using the Rochester Q-jet from my previous Olds 455). I am using an aftermarket mechanical Carter fuel pump, so I think I am getting plenty of juice to the carb. Anyone with suggestions?? Thanks!!
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78 White T/A, Carmine interior, Fisher T-tops, WS-6 package, 3.08 gears, a/c, rear discs. Original 403 with 300,000 miles replaced by new Pontiac 455 (roller everything, 6x-4 heads, Performer manifold, Hooker Headers, Hughes converter, Cliff's Q-jet) - I only get 12 mpg! |
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#2
04-07-2004, 02:04 PM
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I have been putting my new (rebuilt) Pontiac 455 through the paces and have found a problem with periodic bogging/nosing in on heavy acceleration at about 3500 rpm; it has been suggested to me by one shop that my carb's float bowl may be too small (I am using the Rochester Q-jet from my previous Olds 455). I am using an aftermarket mechanical Carter fuel pump, so I think I am getting plenty of juice to the carb. Anyone with suggestions?? Thanks!!
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78 White T/A, Carmine interior, Fisher T-tops, WS-6 package, 3.08 gears, a/c, rear discs. Original 403 with 300,000 miles replaced by new Pontiac 455 (roller everything, 6x-4 heads, Performer manifold, Hooker Headers, Hughes converter, Cliff's Q-jet) - I only get 12 mpg! |
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#3
04-07-2004, 06:00 PM
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Had the same problem with built 428. I had same fuel pump and a Q-jet. Added an electric pump and cured the problem. Car ran 12.10's with the Q-jet.
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#4
04-07-2004, 06:37 PM
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<span class="ev_code_BLUE">mechanical Carter fuel pump</span> I run the same set up And never any problems, Very Strong to redline. Before going the electric pump way. I would check your fuel line and pick up. Then if possible install a pressure gauge in between your pump and carb to help find the problem. Could just be a bad pump or a problem with your carb. But i don,t think your floatbowl size is the problem.
<span class="ev_code_BLUE">Hope this helps.</span>
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--------------------------------------------------------- "And he Asked, Who Owns This Car? With The Peace Sign, Mag Wheels, and the Four on the Floor?? --------------------------------------------------------- |
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#5
04-07-2004, 07:23 PM
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Are you using a fuel pressure regulator? I tried the Mr Gasket regulator and it was so restrictive, it did exactly the same. Piece of crap. A switch to a Holley regulator fixed the problem.
Have you checked filter in carb inlet? Sure sounds like starvation problem and I agree it is unlikely to be float bowl problem. Malcolm |
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