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Old 03-30-2005, 02:28 PM   #1
mokie
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Join Date: Aug 2004
Location: Utah
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Choke

Can anyone get me a better picture of how to adjust the choke on 350 engine. I'm looking at the maintenance books and I'm going . I don't know much about cars but I'm trying to get this done so I can start driving it.

I had a tech tell me that it is staying open. I can start it then it makes a poping noise and shuts off. My 72 blazer is manual trans, the choke is not manual.

Can I also get advise on how to fix it.

HELP!!!

Thanks.
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Old 03-31-2005, 01:23 PM   #2
TrainD5115
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On a cold engine, the choke blade should close when you pump the throttle. This creates the vacuum necessary to pull the fuel into the carb when you crank it. Once the engine fires the choke blade should open slightly so the engine doesn't load up or stall.

This picture shows my Rochester 4bbl with the choke almost completely open.
(fast idle cam on 2nd step) The engine was running in this picture. You can see the choke indexing unit (black circular cover) which controls the rich-lean setting. The shiny new part is the choke pulloff (sometimes called vacuum break) which should open the choke once the engine fires. As the engine warms the choke will continue to open until it is in the full forward position. Hope this helps.
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Old 04-04-2005, 09:46 AM   #3
mokie
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Thanks a ton TrainD5115.
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Old 04-04-2005, 10:36 AM   #4
Brad_Olson
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Since you have a '72 it's possible your Q-Jet is the older 4MV model and uses a divorced choke instead of the carb-mounted version shown on Brad's M4MC Q-Jet. If that's the case the choke is adjusted by bending the rod that runs from the manifold-mounted choke coil to the linkage on the side of the carb.

With the engine cold and not running, manually open the primary throttle all the way - you should see the choke blade snap closed. If it doesn't there's either a problem with the on-carb linkage or the rod from the choke coil to the carb needs to bent a little shorter.

Brad O.

Last edited by Brad_Olson; 04-04-2005 at 10:41 AM.
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