Vacuum leak?

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Old Jun 9, 2010 | 09:54 PM
  #11  
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By plugging up all ports rules out something other than the carb is causing your problem. This would be so you can work on the idling issue but don't attemp to run the car this way. I can deliberately cause idle problems with my vehicles. My truck has a Vacuum modulator on the tranny coming from a manifold port behind the carb and if it gets unplugged creates high idle. My Camaro has a Q-jet where there are 2 large air intake ports in front where the fuel fiter is. If any of these two ports get unplugged the car does turn on but then boggs down. Even a untightened carburetor can cause this. Make sure the carb itself is nice and tight and there are no air leaks between the paper gaskets. Check around the EGR area for leaks. It's tuff to get the choke right, you really have just 1 shot at it when it's cold, unless you unplug the choke power lead but that may not help.

I like what Vete76 said about flooding. That is what exactly was going on with my T/A back in the 80's. Q-jet needed a rebuild. I can rebuild your Q-jet if you lived close, I'm a huge Q-jet fan and I choose this carb over many other carbs when the cars are only mildly modified. The car mags no longer have anything good to say to them because EFI is out there and there are also 4 barrels carbs that are easier to understand and service than the Q-jet.
 
Old Jun 9, 2010 | 10:04 PM
  #12  
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If your car ran well when it was parked,..and only started this problem after you got it out of storage,..then it is NOT your choke adjustment. The choke can't get "out of adjustment" simply from sitting. Based on what you have posted, it is NOT a vaccum leak either. I assure you, it is in the carb and will most likely be a needle valve sticking due to trash or gummed up fuel from sitting. This is an easy fix. Simple remove the needle valve, (reference a shop manual), and clean it up well. Blow out the needle valve seat, and reassemble. While you're in there, clean and "free up" the float assembly. This WILL cure your problem. I've seen it too many times.
 
Old Jun 10, 2010 | 12:22 AM
  #13  
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Originally Posted by Vet76te
If your car ran well when it was parked,..and only started this problem after you got it out of storage,..then it is NOT your choke adjustment. The choke can't get "out of adjustment" simply from sitting. Based on what you have posted, it is NOT a vaccum leak either. I assure you, it is in the carb and will most likely be a needle valve sticking due to trash or gummed up fuel from sitting. This is an easy fix. Simple remove the needle valve, (reference a shop manual), and clean it up well. Blow out the needle valve seat, and reassemble. While you're in there, clean and "free up" the float assembly. This WILL cure your problem. I've seen it too many times.
youre right, i never had this problem last summer so ill go ahead and do this first this weekend and hope all is well after that
 
Old Jun 10, 2010 | 09:36 PM
  #14  
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You might try some carb cleaner in the tank before removing the carb, just on a chance it cleans out enough to be good.
 
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