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Car stumbles at WOT???

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Old 10-30-2009, 10:57 AM
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Car: 1986 Camaro Z28
Engine: 305 Carb
Transmission: 700R4
Axle/Gears: 2.73
Car stumbles at WOT???

Ok it has been a while since I have had a carb engine and this may be a simple question(I hope). The car is a 86 Z28 305 4b Q-jet. It runs fine, idles fine, but at WOT it stumbles real bad. If you let off just a little it runs strong. I have cheked all the vac lines every things seems to be in place. Just wondering if any body might have a idea???
Old 10-30-2009, 11:22 AM
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Car: 1987 SC/1985 TA
Engine: 350/vortec/fitech
Transmission: T56
Axle/Gears: 3.27 9-bolt
Re: Car stumbles at WOT???

peruse:

https://www.thirdgen.org/quadrajet
Old 10-30-2009, 11:52 AM
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Car: 1986 Camaro Z28
Engine: 305 Carb
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Axle/Gears: 2.73
Re: Car stumbles at WOT???

Thanks for the info I will try that and see what happens..
Old 10-30-2009, 04:45 PM
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Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Make sure the secondary rod hanger is pulling the rods up when the AV opens. You can check that with the engine off, air cleaner off, and just push the AV open.

There have been reports of the plastic AV cam falling apart and not pulling the rods out of the orifices (secondary jets) when the AV opens.
Old 11-07-2009, 03:42 PM
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Did you check that yet?

Don't go replacing the carb and distributor (and perhaps intake manifold, and needing to cobble up a torque converter lock up system) over a simple little problem.
Old 11-07-2009, 05:13 PM
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Car: 1986 Camaro Z28
Engine: 305 Carb
Transmission: 700R4
Axle/Gears: 2.73
Re: Car stumbles at WOT???

Originally Posted by five7kid
Did you check that yet?

Don't go replacing the carb and distributor (and perhaps intake manifold, and needing to cobble up a torque converter lock up system) over a simple little problem.
No I have not had a chance to take a look at it today. I was planing to do some looking tomorrow see what happens.
Old 11-07-2009, 06:06 PM
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Car: 1987 SC/1985 TA
Engine: 350/vortec/fitech
Transmission: T56
Axle/Gears: 3.27 9-bolt
Re: Car stumbles at WOT???

I can't imagine what could be more exciting than tinkering with a carbed V8?
Old 11-07-2009, 07:57 PM
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Re: Car stumbles at WOT???

What condition are your spark plugs in? When you say "WOT" are you saying off an idle mashing the pedal to the metal? You're probably not getting enough airflow to open the secondaries until 2000 rpm. I'd make sure your ignition system is in top shape before messing with the carb. sounds like this car is new to you. higher rpm and wot can require higher voltage to fire than at idle. worn plugs need higher voltage to jump a spark. plugs last a long time but if you don't know how long they've been in there you might want to check.
Old 11-09-2009, 09:13 AM
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Car: 1986 Camaro Z28
Engine: 305 Carb
Transmission: 700R4
Axle/Gears: 2.73
Re: Car stumbles at WOT???

Well this problem is now fixed as I just got tired of messing with it and put a holley on yesterday and the car runs great, but the trans is acting weird.
Old 11-09-2009, 12:45 PM
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Car: 1987 SC/1985 TA
Engine: 350/vortec/fitech
Transmission: T56
Axle/Gears: 3.27 9-bolt
Re: Car stumbles at WOT???

You may need a bracket to properly install the TV cable for your trans to the new carburetor. The geometry is very finicky. DO NOT take chances with the TV adjustment on your trans, especially with its likely age and mileage.

Did you replace the computer controlled distributor? Installed an alternate means of locking the torque converter?
Old 11-09-2009, 01:43 PM
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Car: 1986 Camaro Z28
Engine: 305 Carb
Transmission: 700R4
Axle/Gears: 2.73
Re: Car stumbles at WOT???

Originally Posted by naf
You may need a bracket to properly install the TV cable for your trans to the new carburetor. The geometry is very finicky. DO NOT take chances with the TV adjustment on your trans, especially with its likely age and mileage.

Did you replace the computer controlled distributor? Installed an alternate means of locking the torque converter?
Where can I get this bracket? Do I need a new distributor since I had a carb to start with??
Old 11-09-2009, 01:53 PM
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Car: 86' IROC-Z....and 5 other 3rdgens
Engine: 383 hsr
Transmission: built 700r4
Axle/Gears: stock 3.23, 10bolt
Re: Car stumbles at WOT???

im not a carb guy by no means, but iv heard of an accelerator pump bieng an issue for falling on its face at WOT.
Old 11-09-2009, 02:10 PM
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Car: 1987 SC/1985 TA
Engine: 350/vortec/fitech
Transmission: T56
Axle/Gears: 3.27 9-bolt
Re: Car stumbles at WOT???

Check Summit or Jegs for the TV bracket. You may even want to call Holley and get their recommendation.

The timing for your original dist was controlled by the ECM based on feedback from the computer controlled carb. Without this input it's running on a very basic timing curve. YES. You'll want to replace it with a vacuum and mechanical advance unit.

Review the sticky on top of the carb forum for alternative methods of controlling your torque converter lock now.
Old 11-09-2009, 02:18 PM
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Car: 1986 Camaro Z28
Engine: 305 Carb
Transmission: 700R4
Axle/Gears: 2.73
Re: Car stumbles at WOT???

Thanks for the info I will check into all that asap

Damn as more time goes by and I change things makes me miss my 5 and 6sp's
Old 11-09-2009, 02:32 PM
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Car: 1986 Camaro Z28
Engine: 305 Carb
Transmission: 700R4
Axle/Gears: 2.73
Re: Car stumbles at WOT???

Originally Posted by naf
Check Summit or Jegs for the TV bracket. You may even want to call Holley and get their recommendation.

The timing for your original dist was controlled by the ECM based on feedback from the computer controlled carb. Without this input it's running on a very basic timing curve. YES. You'll want to replace it with a vacuum and mechanical advance unit.

Review the sticky on top of the carb forum for alternative methods of controlling your torque converter lock now.
Ok I have looked at all the methods and kits for this lock out thing. So my question is witch one works the best and does not take much to install for the money? I like the b&m one as it looks like it is easy? I like the TCI one for the price.

Last edited by TJ07RK; 11-09-2009 at 03:03 PM.
Old 11-09-2009, 04:11 PM
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Car: 1987 SC/1985 TA
Engine: 350/vortec/fitech
Transmission: T56
Axle/Gears: 3.27 9-bolt
Re: Car stumbles at WOT???

I've no experience, but for the price I think I'd do my own.
Old 11-14-2009, 05:46 PM
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Car: 86 Trans Am
Engine: 350 Roch-4bbl
Transmission: 700R4
Axle/Gears: Normal
Re: Car stumbles at WOT???

buying and installing one
Old 11-14-2009, 05:47 PM
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Car: 86 Trans Am
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Axle/Gears: Normal
Re: Car stumbles at WOT???

Originally Posted by naf
I can't imagine what could be more exciting than tinkering with a carbed V8?
buying and installing a new quadrajet
Old 11-15-2009, 12:46 PM
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Car: 1987 SC/1985 TA
Engine: 350/vortec/fitech
Transmission: T56
Axle/Gears: 3.27 9-bolt
Re: Car stumbles at WOT???

Let us know how it goes.
Old 11-16-2009, 09:00 AM
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Car: 1986 Camaro Z28
Engine: 305 Carb
Transmission: 700R4
Axle/Gears: 2.73
Re: Car stumbles at WOT???

Originally Posted by naf
Let us know how it goes.
Should be good after today. I got the parts to make the trany act right..
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