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Have a 283 4 BBL carter carb that all of sudden refuses to idle down. It was working fine with a high idle when cold but it all of a sudden refuses to idle down when warmed up. I give it a shot with the gas pedal but it won't idle down. I think I messed up with the choke.
Now how do I adjust the choke to work normally again? Pictures would be a great help if anyone can help me. If I can't getting running properly again, then I will just put it away for the winter and try again next year.
Assuming you have a stock hot air type choke, when the car is cold and engine off, breather off:
press and hold the accelerator (as if wide open), can you easily move the choke plate back and forth and does it spring back to almost closed when released? It should.
If it doesn't move freely, the piston in the choke body may have carbon build up that prevents it from moving freely. You would have to disassemble the choke body to clean it.
Did you adjust the choke before this happened? If so, you probably have it pulling the choke on too much. When cold, the choke should be adjusted by rolling the housing until the choke JUST closes. As the car warms up, the choke should go to increasingly less closed position. After the car is warm, it shouldn't close at all when you move the gas pedal rod.
If the choke is opening fully and it still idles fast, you need to back out the idle screw that is on the driver side bottom and rides on the cam that moves with the choke plate.
Summary: check to see if the choke is closing at cold, opening fully at hot, and the idle screw is not turned in so far that it idles fast even when the choke is off. Sounds like your choke is either adjusted on too tight, is binding, or you have your idle screw in too far.
Assuming you have a stock hot air type choke, when the car is cold and engine off, breather off:
press and hold the accelerator (as if wide open), can you easily move the choke plate back and forth and does it spring back to almost closed when released? It should.
If it doesn't move freely, the piston in the choke body may have carbon build up that prevents it from moving freely. You would have to disassemble the choke body to clean it.
Did you adjust the choke before this happened? If so, you probably have it pulling the choke on too much. When cold, the choke should be adjusted by rolling the housing until the choke JUST closes. As the car warms up, the choke should go to increasingly less closed position. After the car is warm, it shouldn't close at all when you move the gas pedal rod.
If the choke is opening fully and it still idles fast, you need to back out the idle screw that is on the driver side bottom and rides on the cam that moves with the choke plate.
Summary: check to see if the choke is closing at cold, opening fully at hot, and the idle screw is not turned in so far that it idles fast even when the choke is off. Sounds like your choke is either adjusted on too tight, is binding, or you have your idle screw in too far.
Thanks for your response. Yes it is a stock hot air choke. What started this whole problem was the fast idle. When I tried adjusting the CARB IDLE nothing changed. This is where I am getting confused. Is there a separate idle related to the actual choke? All of this is on the drivers side of the carb. Is there any possible chance you could send me a picture of what I should be seeing on that side of the carb and which idle screw I should be adjusting? The choke (flaps) on the carb move freely without any resistance. What position should these flaps be in when starting from a cold start??
Thanks for your response. Yes it is a stock hot air choke. What started this whole problem was the fast idle. When I tried adjusting the CARB IDLE nothing changed. This is where I am getting confused. Is there a separate idle related to the actual choke? All of this is on the drivers side of the carb. Is there any possible chance you could send me a picture of what I should be seeing on that side of the carb and which idle screw I should be adjusting? The choke (flaps) on the carb move freely without any resistance. What position should these flaps be in when starting from a cold start??
I get the feeling you didn't read my post.
When cold, the choke should be adjusted by rolling the housing until the choke JUST closes. As the car warms up, the choke should go to increasingly less closed position. After the car is warm, it shouldn't close at all when you move the gas pedal rod.
When cold, the choke should be adjusted by rolling the housing until the choke JUST closes. As the car warms up, the choke should go to increasingly less closed position. After the car is warm, it shouldn't close at all when you move the gas pedal rod.
Yes my apologies. I am not certain what you mean by the "housing". What is the housing exactly? Is that where it all links to? And what about the fast idle...am I misinterpreting the wrong idle screw? Do you have a picture of this housing?
There's only one idle screw adj, shown by the red arrow. When the choke is fully open (off), the tip of that screws touches the lower end of the cam shown. After the car is warm, you can adjust your idle screw for the rpm's you want. The fast idle is provided by the cam lobe being moved by the choke so that it keeps the accelerator rod from going back to its lowest position.
None of this will work correctly till you adjust the choke as I explained earlier. Full on when cold, full off when hot. The choke is adjusted by loosening the three screws that hold the ring around the choke housing and rotating one way for more and one way for less closing, then tighten the screws. If you have no experience with this, I suggest you may want to find someone to help who has done it before.
Ha! 65ggvert types faster than me! So, I repeated some things.
Look -- the WCFBs don't have a separate fast idle screw adjustment, nor do they use discrete steps as other carbs often do. There is an offset cam that rides under the REGULAR curb idle screw that rotates with the closing of the choke to raise the idle.
To wit, you have to set the hot curb idle to specs...the choke spring and linkage control the FAST idle. The choke housing is the black plastic bakelite round device on the PS side of the carb...three screws to remove it and there is a baffle plate and gasket. If you remove it you will see the action of the piston as 65GGvert describes. If the piston cylinder is carbonized the choke will stick..
Often the hot air tube into the choke housing gets corroded where it enters the exhaust manifold and allows fouled, carbonized exhaust gases into the piston arrangement. That tube should go THROUGH the exhaust manifold entirely.
Last edited by Frankie the Fink; 09-20-2017 at 11:58 AM.
There's only one idle screw adj, shown by the red arrow. When the choke is fully open (off), the tip of that screws touches the lower end of the cam shown. After the car is warm, you can adjust your idle screw for the rpm's you want. The fast idle is provided by the cam lobe being moved by the choke so that it keeps the accelerator rod from going back to its lowest position.
None of this will work correctly till you adjust the choke as I explained earlier. Full on when cold, full off when hot.
So the housing you speak of is where the BIG SCREW is at the bottom. And FULL ON when cold is the choke (flaps) closed position?
Read my post and the pic provided.. You are on the WRONG side of the carb for the choke housing.
So "ROLLING THE CHOKE HOUSING UNTIL IT CLOSES" to have it adjusted for cold start. Back to ...what and where is the choke housing and rolling it as in just turning it?
Sorry, I am just trying to gain some basic knowledge.
Take the choke housing off SHOWN in my picture...you will see the 'hook' in the cover that grabs the spring, as you turn the cover, the pressure on the coiled spring increases and drives the choke plate closed. Really, it doesn't get much simpler.
Take the choke housing off SHOWN in my picture...you will see the 'hook' in the cover that grabs the spring, as you turn the cover, the pressure on the coiled spring increases and drives the choke plate closed. Really, it doesn't get much simpler.
Yes! You'll need two wrenches to remove the tube or you'll tear the plastic snout off of the housing...
Definitely hold the hex on the housing and loosen the nut holding the hot air tube BEFORE you rotate the housing, then tighten back up lightly. I still recommend you find someone familiar with the adjustment to go over it with you the first time, then you will better understand how it works.
Definitely hold the hex on the housing and loosen the nut holding the hot air tube BEFORE you rotate the housing, then tighten back up lightly. I still recommend you find someone familiar with the adjustment to go over it with you the first time, then you will better understand how it works.
I agree....some experienced help is not a bad idea.
09-19-2017, 10:13 PM
58 Carter Carb Choke
