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Quadrajet Choke Won't Close

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Old Jun 11, 2019 | 10:29 AM
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Default Quadrajet Choke Won't Close

69 with 350. Trying to figure out why my choke will not close when engine is cold. Could it be a linkage problem or is there a way to adjust it? Typical divorced choke with the bimetal coil on the manifold. Runs excellent when warmed up. I'm sure it's something simple but don't know where to start, Thanks for any advice.
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Old Jun 11, 2019 | 10:56 AM
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No photos. Can't advise without photos.
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Old Jun 11, 2019 | 11:08 AM
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Some pics. Engine cold. Throttle pumped twice.


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Old Jun 11, 2019 | 04:58 PM
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The first thing I would do is test the choke spring to see if it's trying to pull down when cold. Also make sure that the choke rod is connected.
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Old Jun 11, 2019 | 05:23 PM
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Something is jammed in your linkage. Notice that the short, dog-legged rod (going from your choke shaft lever to the choke pulloff with the spring behind it) has the spring fully compressed. That spring should not be compressed - it should be pushing that lever aft and should be fully extended. The fact that it's jammed all the way forward means you have something incorrectly assembled in the choke linkage on the carb, and it's got you locked wide open.

Lars
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Old Jun 11, 2019 | 06:23 PM
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Thanks for the replies. The choke spring is pulling down but very weakly. Could it be I have the wrong length link from the choke spring? Maybe it's too long?? Not pulling down hard enough? The choke seems ok once I manipulate the weight by hand but will remain on high idle even when warmed up until manipulated by hand again. Only then will itl revert to it's old (wrong) position.

Last edited by 69L46vert; Jun 11, 2019 at 06:41 PM. Reason: Added "weight"
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Old Jun 11, 2019 | 08:28 PM
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Believe me, Lars is the zen master of Quadrajet & Holley carbs. He made my quadrajet purr like a kitten.
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Old Jun 11, 2019 | 10:36 PM
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Originally Posted by 69L46vert
Thanks for the replies. The choke spring is pulling down but very weakly. Could it be I have the wrong length link from the choke spring? Maybe it's too long?? Not pulling down hard enough? The choke seems ok once I manipulate the weight by hand but will remain on high idle even when warmed up until manipulated by hand again. Only then will itl revert to it's old (wrong) position.
See my note above in post #5. Your choke coil is pulling down, as evidenced by the rod being in the bottom of the attach slot. The lever is not moving because it is incorrectly assembled or jammed.
Lars

Last edited by lars; Jun 11, 2019 at 10:38 PM.
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Old Jun 12, 2019 | 07:06 AM
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Thank Lars. I'll look at it again today.
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Old Jun 12, 2019 | 10:30 AM
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Following up. The problem seems to be solved. This morning I shortened the choke rod (from the bimetal coil) about 3/16", maybe 1/4". It was pulling down but just barely. The fact that the lever was not down as far as it should have been when cold was causing the linkage to jam so I never had any choke or fast idle. BTW I bought this rod from a reputable Corvette house. Simply not the right one. I had never used the car in cold weather since rebuild so it wasn't very noticeable. Today after the alteration the car started and I had fast idle which gradually decreased just like it's supposed to. I'm waiting now for it to cool down again and retest. Thanks to all for the help and ideas.
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Old Jun 12, 2019 | 05:15 PM
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Glad you got it figured out. I used this to help me when I needed to adjust mine a few years ago:https://www.hemmings.com/blog/articl...ke-adjustment/
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