Choke won't close?
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Choke won't close?
I have a 86 f150, 300 1bbl carb, c6 tranny.
I bought a rebuilt carb. Everything but the choke works correctly. It stays open. When you start the truck up, it'll open, like it should...and stay open. Which obviously means its going to run lean...really lean. This also makes it where because its sucking in so much air, it won't idle down and almost dies when you rev it up.
Help! Can anyone give me some ideas?
I bought a rebuilt carb. Everything but the choke works correctly. It stays open. When you start the truck up, it'll open, like it should...and stay open. Which obviously means its going to run lean...really lean. This also makes it where because its sucking in so much air, it won't idle down and almost dies when you rev it up.
Help! Can anyone give me some ideas?
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Oh, okay. I feel smart.
The plate that opens the choke once you start, that is where the idle is controled, correct? The screw's go up against it. So that little plate, is it suppose to flap in the wind, or should it not hardly move at all?
The plate that opens the choke once you start, that is where the idle is controled, correct? The screw's go up against it. So that little plate, is it suppose to flap in the wind, or should it not hardly move at all?
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From: Virginia
The choke is completely out of the picture, and should be wide open after the engine is warmed up. It should never "flap in the breeze". When the engine is warmed up, it should be held open.
The choke is used to richen the mixture when the engine is cold. Also when the choke is activated when cold, it raises the idle rpm to also aid in warmup of the engine when the oil is stiff, and the intake manifold is cold.
The choke is used to richen the mixture when the engine is cold. Also when the choke is activated when cold, it raises the idle rpm to also aid in warmup of the engine when the oil is stiff, and the intake manifold is cold.
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Originally Posted by Sport45
Which "small little bracket"? Can you post a picture?
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From: Virginia
Find the picture again, hold your mouse over the picture and right click. Scroll down and click "properties". When the box comes up, one of the lines will have the http url in it. Hold the mouse over the http and click and drag over the whole thing to turn it dark blue. Then hold the mouse over the dark blue, right click and hit "copy".
Come back here, reply to this post, and hold your mouse over the field where you type in your message. Right click and hit "paste". That will put the link for the picture in your message, and we can click on the link to see it.
Come back here, reply to this post, and hold your mouse over the field where you type in your message. Right click and hit "paste". That will put the link for the picture in your message, and we can click on the link to see it.
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From: Virginia
That piece is the fast idle cam. You can see the screw that bumps against it to the rear of the cam.
When the choke closes, the rod coming down from the round black housing pulls up on the cam, though it does not have enough strength to pull the cam up. That's what you do when you hit the gas pedal once or twice in the morning before starting the engine. You relieve the pressure between the screw and the cam, and that lets the rod from the choke pull the cam up. Then the cam holds the throttle open, making the engine fast idle.
When the choke starts warming up, it starts to open. To let it work freely, they have that slot in the cam so the rod from the housing can slide down. But it will still usually fast idle till you "kick" the throttle. That relieves the pressure between the screw and the cam, and lets the cam fall back down. That is what that big hunk of metal is on the forward part of the cam. With all that weight on the end, gravity helps it fall back down when you kick the throttle.
When the choke closes, the rod coming down from the round black housing pulls up on the cam, though it does not have enough strength to pull the cam up. That's what you do when you hit the gas pedal once or twice in the morning before starting the engine. You relieve the pressure between the screw and the cam, and that lets the rod from the choke pull the cam up. Then the cam holds the throttle open, making the engine fast idle.
When the choke starts warming up, it starts to open. To let it work freely, they have that slot in the cam so the rod from the housing can slide down. But it will still usually fast idle till you "kick" the throttle. That relieves the pressure between the screw and the cam, and lets the cam fall back down. That is what that big hunk of metal is on the forward part of the cam. With all that weight on the end, gravity helps it fall back down when you kick the throttle.