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  #1 (permalink)  
Old 09-24-2013, 11:22 AM
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Default Edelbrock carb problems

I know this is a Holley sub-forum, but there isn't one for Edelbrock carbs...

My buddy has a 347 SBF stroker with a dual quad setup with two Edelbrock 500cfm mechanical secondary carbs ( I know, overcarb'd). They are setup with a progressive linkage - the rear carb with choke is the main carb. It hits about 20% before the front carb (no choke) starts opening. The secondaries on the primary carb start to open about 40% throttle... anyway, that's not the problem.

The problems is that when the car is cold - choke on for the main carb, it idles fine. Once the choke turns off, it idles fine at around 900rpm. However, once the car/carb gets hot after driving for a few minutes, the idle stays up at around 1500rpm. Blipping the throttle doesn't help. Pulling the pedal up does not help lower the idle back down. Putting a heavy spring on the primary carb resolves the issue but makes the throttle pedal hard to push and impossible to feather.

Any ideas? I'm thinking maybe a slightly bent throttle rod. When the carb heats up, it sticks a little. Any other ideas?

There is no rubbing of the linkage on the filters or intake.
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Old 09-24-2013, 11:54 AM
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Not sure if this works on an Ed carb (or if they even have a baseplate) but when my Demon carb exhibited the same symptoms, I ended up replacing the entire base plate. Problem solved.
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Old 09-24-2013, 03:14 PM
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Sounds like it's not coming off the of the fast idle cam. Usually an easy screwdriver fix.

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Old 09-24-2013, 07:06 PM
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I have the twin eds on a 351w had very same problem. Its was the fast idle came. Had to back off scew and spray a little lube on the rod.
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Old 09-26-2013, 06:09 AM
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Thanks guys. I will try the above.
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Old 09-29-2013, 01:08 PM
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The fast idle cams are "weighted" and could be binding on their pivots.
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Old 09-30-2013, 08:40 PM
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Quote:
Originally Posted by Gaz64 View Post
The fast idle cams are "weighted" and could be binding on their pivots.
How do you go about checking to see if they are binding on their pivots?
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Old 10-01-2013, 12:45 AM
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Quote:
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How do you go about checking to see if they are binding on their pivots?
Disconnect the rod to the cam, the cam should be free to rotate on it's pivot.
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