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Carb is choking car

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Old Mar 15, 2011 | 05:42 PM
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Carb is choking car

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This picture is what it looks like when it runs great

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The thing circled, as i do not know what to call it(what love to know what to call it and what it does), will close up allowing no air into the fuel mixture

So I go and push this lever that opens it up, then my car starts right up, will post pictures, Bare with me on the terms I am new to auto repair

Last edited by Reddeath210; Mar 16, 2011 at 02:50 PM.
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Old Mar 16, 2011 | 07:05 AM
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Re: Carb is choking car

Not sure what you mean by '2nd barrel'. Please provide some pics and perhaps a better description of what's going on. Sounds like a choke issue, but not sure.
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Old Mar 16, 2011 | 05:08 PM
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From: Hampton, Virginia
Car: 87 Camaro Z-28
Engine: 305 LG4 w/ E4ME carb
Transmission: 700R4
Axle/Gears: 2.73
Re: Carb is choking car

Have you tried a can of $3 carb cleaner and spraying the outside linkage/parts? it's possible they are sticking.
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Old Mar 17, 2011 | 04:11 AM
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Re: Carb is choking car

The thing circled in your pic is the choke. It's purpose is to richen the engine for better drivability and cold starts, but ONLY when the engine's cold. If it's staying shut all the time ( untill you manually open it ), it could just be sticky linkage.

Last edited by DoubleV; Mar 17, 2011 at 05:29 PM.
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Old Mar 17, 2011 | 12:08 PM
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From: Saskatoon, SK, Canada
Car: '83 Z28, '07 Charger SRT8
Engine: 454ci, 6.1 Hemi
Transmission: TH350, A5
Axle/Gears: 2.73 posi, 3.06 posi
Re: Carb is choking car

What you have circled is the choke - the moving plate is called the choke plate.

When the engine is cold, it should be mostly closed (maybe an 1/8" to 1/4" gap on the front and back of the plate to the carb body). The purpose of this is NOT to restrict airflow through the carb when it is cold, but instead it is to help richen up the fuel mixture.

When that plate is closed, it creates a bit of vacuum underneath it, which helps to draw fuel from the main fuel circut as well as the idle circuit, instead of just the idle circuit. The engine needs this extra fuel when its started cold, as well as needing to idle faster than normal (typically set to around 1300-1500rpm) so that it can start and run without stalling and also warm up quickly. Once the engine has a bit of heat in it, that plate should be completely open, as the extra fuel is no longer needed. It should also settle down to a normal idle when you tap the throttle.
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Old Mar 17, 2011 | 01:14 PM
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Re: Carb is choking car

When the engine is cold, it should be mostly closed (maybe an 1/8" to 1/4" gap on the front and back of the plate to the carb body). The purpose of this is NOT to restrict airflow through the carb when it is cold, but instead it is to help richen up the fuel mixture.
I have used the carb cleaner on it and it still does it. The choke doesn't really move at all. I have turn on the car gave it a nice amount of gas and it doesnt move. Does anyone know what makes the choke move?
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Old Mar 17, 2011 | 01:18 PM
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Car: 86 iroc
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Re: Carb is choking car

the choke mech on the side(round thing)could be bad,is the wire hooked up?
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Old Mar 17, 2011 | 01:22 PM
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Re: Carb is choking car

the choke mech on the side(round thing)could be bad,is the wire hooked up?
we took the choke mech apart, and it has some springiness to it still, i dont know what wire u are talking about though.
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Old Mar 17, 2011 | 03:59 PM
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Car: 82 Berlinetta/57 Bel Air
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Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
There should be a single wire plugged into the black round plastic piece with the coiled spring in it - that black round plastic piece is called the "choke thermostat". The wire supplies 12 volts to the "choke thermostat" to warm it up when the engine is running. It takes several minutes of the engine running for it to warm up enough to open the choke plate.

https://www.thirdgen.org/forums/carb...e-rebuild.html , scroll down to the exploded view, part #46. The factory called it the "stat cover" (as in "thermostat" cover). Make sure when you put the thermostat back on that the coil spring properly engages the choke coil lever, #42.
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Old Mar 17, 2011 | 05:23 PM
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Re: Carb is choking car

Originally Posted by Air_Adam
The purpose of this is NOT to restrict airflow through the carb when it is cold, but instead it is to help richen up the fuel mixture. When that plate is closed, it creates a bit of vacuum underneath it, which helps to draw fuel from the main fuel circut as well as the idle circuit, instead of just the idle circuit.
Yes this is true. My description was just meant for the OP to get a 'laymans' view on what's going on and wasn't meant to be technically accurate ( which it isn't ). I thought it would be easier for him to understand my simplistic description rather than get too technical which can sometimes be harder to grasp. Perhaps I should've just explained it accurately though. I will reword it as to not cause confusion.

Last edited by DoubleV; Mar 17, 2011 at 05:28 PM.
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