350 won't run off throttle

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  #1  
Old 02-07-2012 | 10:00 PM
mike6208's Avatar
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Default 350 won't run off throttle

got the 350 started. but wont stay running off full throttle, video below


rebuilt 355
quadrajet carb
open headers for now
i set the timing as per a youtube video that walks you threw it.


any ideas to get her running? thanks all


7218485f.mp4 video by pfft84 - Photobucket
Cant see my hand in the video but i was on full throttle when it ran, as soon as i let it go, it dies. and the smoke in the vid is from the painted headers
 
  #2  
Old 02-07-2012 | 11:41 PM
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I'd start by cranking up the idle setscrew to get it to keep running. Once you've got it high enough to stay running, then you can adjust the idle air screws to make it run smooth. Sounds like you've got open headers, so it's going to add to the difficulty in getting a smooth idle.
I use a vacuum gauge to set idle and timing on my cars. Plug the vacuum gauge in and adjust each air screw to the highest vacuum, then move to the other screw. Repeat this back and forth until you can't get it any higher vacuum. Then set the idle speed setscrew to get the idle to around 700 rpm in neutral. Check timing after that, and adjust to factory setting, or highest vacuum.
Once you've got exhaust on it you'll need to readjust everything again.
PS-Before you start, turn the screws on idle air mixture all the way in, then back them out 1 1/2 turns. That will give you a good base point.
 
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Old 02-07-2012 | 11:58 PM
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thanks for the info, i'm going to get the thing started first and run alittle, just to make sure the motor works, then ill leave it untill i get an exhaust on it, then fully set it right.
 
  #4  
Old 02-08-2012 | 06:58 AM
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Sounds like a vac. leak or fuel mixture adjustment. Is the carb rebuilt? If not one place for a leak can be at the base or at the throttle point. A cautious but simple test of spray starter fluid near there will give you temp resolution and then resume back to no idle.
 
  #5  
Old 02-08-2012 | 11:39 AM
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I'd expect a high idle situation with a vacuum leak, and then a further increase with a leak test.
 
  #6  
Old 02-08-2012 | 12:55 PM
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Is the carb dumping fuel into the motor? If the Secondary meter wells have not been Sealed right they will leak into the intake.... if you open the secondary throttle plates... Upper and lower and shime a flashlight into the intake you can see them dripping raw fuel on to the floor of the intake then the secondarys need to be resealed.. it will run super rich and will never idle right until this problem is solved... Just one more thing to look for.
 
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Old 02-08-2012 | 02:28 PM
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From the slow cranking I would say back the timing off a bit.
 
  #8  
Old 02-08-2012 | 05:24 PM
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think im going to wait untill i get the full exhaust before i get into starting it and tuning.

was wondering if you guys can check my vac setup, see if i have everything right in the pics below





 
  #9  
Old 02-08-2012 | 07:37 PM
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Looks like it's OK from what I can see on the carb. Do you have any other valves or solenoids externally that have vacuum line to them?
 
  #10  
Old 02-08-2012 | 07:39 PM
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Quote Tiny TIM " God Bless Us every each one!"
 



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