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Why does it bog?

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Old May 25, 2009 | 09:32 PM
  #1  
blackandgoldl69's Avatar
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From: Elizabethtown,Ky
Car: 1984 camaro z28
Engine: L69 H.O
Transmission: 700r4
Axle/Gears: 3.73
Why does it bog?

should my carb bog down on quick throttle movements its fine if you increase the throttle normally but if you slam the throttle really fast it seems to bog here is a video to show you what i mean
http://s14.photobucket.com/albums/a3...t=SANY6590.flv
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Old May 26, 2009 | 01:53 PM
  #2  
five7kid's Avatar
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
How is it when you drive it?

What distributor are you using?

Where is your timing set?
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Old May 27, 2009 | 10:12 AM
  #3  
mpb74's Avatar
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Joined: Mar 2008
Posts: 251
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From: South Carolina
Car: 1986 Iroc-Z
Engine: 355 Phase 2 Bowtie heads
Transmission: 700r4
Axle/Gears: 342
Re: Why does it bog?

your four barrel could be coming in too soon. i have the same set up and it was a problem for me.
also, i bought a rebuild kit with brass floats, brass seats,and a different vacum secondary. my vacum secondary now has a bracket where i can change my springs, it looks like a street avenger now. big improvement!
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Old May 27, 2009 | 03:57 PM
  #4  
Air_Adam's Avatar
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Posts: 9,067
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From: Saskatoon, SK, Canada
Car: '83 Z28, '07 Charger SRT8
Engine: 454ci, 6.1 Hemi
Transmission: TH350, A5
Axle/Gears: 2.73 posi, 3.06 posi
Re: Why does it bog?

Its a Holley - your accelerator pump linkage is probably out of adjustment (too loose). Get it all snugged back up and I'll bet most if not all of the bog goes away.
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Old May 27, 2009 | 04:27 PM
  #5  
shermanwizard's Avatar
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From: Alamance, NC
Car: 1992 Camaro RS
Engine: 305 TBI
Transmission: T-5
Axle/Gears: 3.27
Re: Why does it bog?

Vacuum secondaries are only supposed to open under load while driving. If they are opening while you throttle by hand then the spring is too soft and the car will fall flat on its face until the fuel can catch up with the air.
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Old May 27, 2009 | 04:30 PM
  #6  
shermanwizard's Avatar
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From: Alamance, NC
Car: 1992 Camaro RS
Engine: 305 TBI
Transmission: T-5
Axle/Gears: 3.27
Re: Why does it bog?

Why did you lose the Q-jet carb? It flows around 770cfm as is. Lightly modified it can reach 850cfm.
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Old May 27, 2009 | 09:19 PM
  #7  
blackandgoldl69's Avatar
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Joined: Jun 2007
Posts: 428
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From: Elizabethtown,Ky
Car: 1984 camaro z28
Engine: L69 H.O
Transmission: 700r4
Axle/Gears: 3.73
Re: Why does it bog?

It stumbles when you slam it from a dead stop when driving but if you ease into it for a second the slam it it will light the tires up and take off. I got the shop to set the timing back to stock cause i don't own a timing light i dunno what the stock timing was but thats what he set it to. The distributor is an accel vac advanced stock replacement with an accel super coil and ac delco plugs. i lost the quadra jet cause i tried to rebuild it and failed and didnt have time to send it to someone to get rebuilt cause i really needed it for a daily vehicle so i just bought the holley.
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Old May 27, 2009 | 10:19 PM
  #8  
shermanwizard's Avatar
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From: Alamance, NC
Car: 1992 Camaro RS
Engine: 305 TBI
Transmission: T-5
Axle/Gears: 3.27
Re: Why does it bog?

Is the engine stock or have you modified it?
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Old May 28, 2009 | 03:21 AM
  #9  
Air_Adam's Avatar
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Joined: Oct 2002
Posts: 9,067
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From: Saskatoon, SK, Canada
Car: '83 Z28, '07 Charger SRT8
Engine: 454ci, 6.1 Hemi
Transmission: TH350, A5
Axle/Gears: 2.73 posi, 3.06 posi
Re: Why does it bog?

Originally Posted by blackandgoldl69
It stumbles when you slam it from a dead stop when driving but if you ease into it for a second the slam it it will light the tires up and take off. I got the shop to set the timing back to stock cause i don't own a timing light i dunno what the stock timing was but thats what he set it to. The distributor is an accel vac advanced stock replacement with an accel super coil and ac delco plugs. i lost the quadra jet cause i tried to rebuild it and failed and didnt have time to send it to someone to get rebuilt cause i really needed it for a daily vehicle so i just bought the holley.
Classic description of what happens when the accelerator pump linkage gets sloppy and out of adjustment. When it gets loose, it will give the pump shot too late after the throttle has been cracked open, and probably too little of a shot too. This is why it will bog - its leaning out badly when you snap the throttle open. Check the accelerator pump linkage, I'll bet it feels somewhat loose and sloppy. Tighten it up and I bet your problem is solved. All you need to do is just adjust all the slack out of it. Easy.
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Old Jun 1, 2009 | 11:46 PM
  #10  
graymaro87's Avatar
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Joined: Jun 2009
Posts: 15
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From: Lemoore, CA
Car: 87 Z28
Engine: 305 4bbl
Re: Why does it bog?

Originally Posted by Air_Adam
Classic description of what happens when the accelerator pump linkage gets sloppy and out of adjustment. When it gets loose, it will give the pump shot too late after the throttle has been cracked open, and probably too little of a shot too. This is why it will bog - its leaning out badly when you snap the throttle open. Check the accelerator pump linkage, I'll bet it feels somewhat loose and sloppy. Tighten it up and I bet your problem is solved. All you need to do is just adjust all the slack out of it. Easy.

would the accelerator pump linkage being loose also cause a bog from a dead stop to a hard acceleration?????
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Old Jun 2, 2009 | 01:31 AM
  #11  
Air_Adam's Avatar
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Joined: Oct 2002
Posts: 9,067
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From: Saskatoon, SK, Canada
Car: '83 Z28, '07 Charger SRT8
Engine: 454ci, 6.1 Hemi
Transmission: TH350, A5
Axle/Gears: 2.73 posi, 3.06 posi
Re: Why does it bog?

Originally Posted by graymaro87
would the accelerator pump linkage being loose also cause a bog from a dead stop to a hard acceleration?????
Yes.
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Old Jun 2, 2009 | 01:38 PM
  #12  
five7kid's Avatar
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
It would bog if the timing was set to stock rather than what a non-computer distributor timing should be set to.
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Old Jun 2, 2009 | 06:04 PM
  #13  
graymaro87's Avatar
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Joined: Jun 2009
Posts: 15
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From: Lemoore, CA
Car: 87 Z28
Engine: 305 4bbl
Re: Why does it bog?

im going to start a different thread on my issue. i dont want to steal any help from blackandgoldl69
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